• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.500-506
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• 2011

The deep mixing method, which is generally considered as a method for improving soft ground, is assessed in terms of its applicability for urban construction. Using small equipment tailored to perform deep mixing in congested urban areas, deep mixing was performed to reinforce the foundation ground of a retaining wall in a redevelopment site in Seoul. Strengths characteristics, construction vibrations and displacements induced to an adjacent old masonry wall were evaluated by laboratory tests and field monitoring. The results indicate that the strength of ground was improved appropriately whilst the vibrations and displacements induced by deep mixing were slight enough to satisfy the general requirements for construction works in urban environments. Therefore, it is concluded that deep mixing method can be a practical option for foundation methods in urban construction works where minimizing noise and vibrations is an important concern.

• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.399-405
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• 1986

Corn starch was saccharified without cooking in an agitated bead reaction system. Uncooked corn starch was effectively hydrolyzed even at the concentration as high as 39%(w/v). After 24 hours. the extent of saccharification reached at 92%, which corresponds glucose concentration of 425g/L. Fed-batch feeding of starch was more effective than batch feeding for saccharification of uncooked corn starch. The composition of hydrolysated of uncooked starch was analyzed. which was composed of 95% glucose, 0.7% of maltose, and 4.5% of high saccharide, similar with that of cooked starch. The hydrolysate can be successfully utilized for HFCS manufacture. The starch liquefying and saccharifying enzyme was relatively stable even be the physical impact of the attrition-milling media. The enzyme stabilizer, $Ca^{++}$, played an essential role in preventing the enzyme deactivation caused by the physical impact.

• Journal of Adhesion and Interface
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• v.10 no.1
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• pp.11-16
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• 2009

The microcapsules containing rosmarinic acid were prepared in this research. Rosmarinic acid is known that it is effective to care the winkles. Chitosan was used as a wall material, and glutaraldehyde was used as a crosslinking agent, and the microcapsules were prepared by the water-in-oil (W/O) emulsion method. In this method Span80 was used as an emulsifier, and mineral oil was used as a medium material. Perfectly spherical microcapsules were obtained in the size range of $0.5{\sim}0.9{\mu}m$. The effects of emulsifier concentration and stirring speed on the average particle size and distribution, and encapsulation efficiency were investigated. The release behavior of the microcapsules with different amount of the crosslinking agent and different emulsifier concentrations were also investigated.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.34-37
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• 2001

폐수처리분야에 널리 사용되어 온 펜톤산화반응을 응용한 Fe$^{\circ}$/$H_2O$$_2$시스템을 이용하여 고농도 유류오염 미세호양(100$\mu\textrm{m}$이하)의 화학적 산화처리 실험을 수행하였다. 반응은 100$m\ell$, 삼각프라스크에 오염토양(5g)과 반응시약을 주입한 후 자석교반기를 이용하여 회분 식으로 진행하였으며 일정 시간(0, 1, 2, 4, 8, 24hr)별로 TPH를 측정하였다. 그리고 각 조건별 시간에 따른 반응특성을 살펴보았다. 일반적으로 알려진 펜톤산화반응의 수요 반응조건인 초기 pH /$H_2O$$_2$ 및 Fe$^{\circ}$의 주입농도, 그리고 초기 디젤오염농도의 조건을 변화하며 각 조건별 처리효과를 알아보았다. 본 연구결과에서 최적 pH조건은 3인 것으로 나타났으며, 분말철(Fe$^{\circ}$)과 $H_2O$$_2$의 주입농도를 증가함에 따라 오염토양의 TPH 제거효율도 비례적으로 향상되었다. 초기오염농도에 따른 최종 처리효율은 큰 차이가 없었으나. 고농도 오염일수록 제거된 디젤의 총량은 크게 나타나. 본 논문에서 제시한 방법이 고농도 오염토양일수록 더 큰 효과를 얻을 수 있음을 보여주었다. 대부분의 반응이 반응개시 후 약 8시간 이내에 이루어졌는데, 반응에 수반되는 pH 상승과 그에 따른 반응성의 저감효과를 일정 pH 조절에 의해 감소시킴으로써 반응성의 향상을 좀 더 높일 수 있을 것으로 판단된다. 결론적으로, Fe$^{\circ}$/$H_2O$$_2$시스템을 이용한 화학적 산화처리방법은 경제성과 처리성능에서 고농도 유류오염 미세토양의 효율적인 처리방안으로서 향후 적용 가능성이 높을 것으로 기대된다.

• KSBB Journal
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• v.13 no.1
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• pp.58-64
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• 1998

An extracellular lipid-producing strain, Rhodotorula glutinis K-501, was isolated from soil. The extracellular lipid produced by the cell was found to have good and stable emulsifying activity. Factors affecting the extracellular lipid production were studied to optimize culture conditions for maximum production. Sucrose and ammonium sulfate were selected as best carbon and nitrogen sources, respectively because they gave the highest concentration of product. The optimum C/N ratio was 50. Optimum concentrations of $KH_2PO_4,\; Na_2HPO_4, \;and\; CaCl_2 $were 3.5, 1.0, 0.75, and 0.1g/L, respectively. The optimum temperature and initial pH were determined as $22^{\circ}C$ and 7.0, respectively. When the batch culture was conducted with a sucrose concentration of 60g/L under the optimized conditions, extracellular lipid was produced to a concentration of 8.1g/L with a high production yield of 51.9% based on dry cell weight.

• Journal of Adhesion and Interface
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• v.9 no.2
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• pp.8-15
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• 2008

Microcapsules have been widely used in cosmetics and pharmacology as controlled delivery devices of various active materials. Chitosan is the second most plentiful natural biopolymer with biocompatibility and nontoxicity. The chitosan microcapsules were prepared by the water-in-oil (W/O) emulsion method using glutaraldehyde as a crosslinking agent. Span80 was used as an emulsifier, and mineral oil was used as a medium material. Perfectly spherical microcapsules were obtained in the size range of $2{\sim}10{\mu}m$. The effects of emulsifier concentration and stirring speed on the average particle size and distribution were investigated. Encapsulation and release behavior of the microcapsules with different amount of the crosslinking agent (glutaraldehyde), different chitosan contents and different emulsifier concentration conditions were also investigated. The release rate of riboflavin was controlled by the crosslinking density of the chitosan and amount of emulsifier in the preparation of the microcapsule.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.186-192
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• 2017

In this study, water in oil (W/O) emulsion fuel was prepared with surfactant mixture of OIMS90 and NP12 by varying ratio of water to bunker-C oil, surfactant concentration and composition, emulsification time, stirring intensity, temperature and mixing time. Diesel engine performance and exhaust emissions were measured and analyzed with prepared emulsified fuel and compared with those measured using bunker Coil. The results indicated that bunker C emulsion fuel stabilized by surfactant mixture of OIMS90 and NP12 is efficient in reducing emissions of particulate matter, $NO_2$, CO, $CO_2$ and $SO_2$. The biggest reduction in exhaust emission was achieved by using emulsion fuel prepared by OIMS90/NP12 = 4 : 6, 500 ppm of total surfactant concentration and 10% water content at $80^{\circ}C$. Boiler efficiency test measured with emulsion fuel showed excellent energy efficiency compared with bunker C oil.

• KSBB Journal
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• v.18 no.5
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• pp.363-370
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• 2003

A filamentous fungus, strain FM04 producing amylase was isolated from rotten yam peels and potatoes. The favorable conditions of cultivation factors such as, temperature, pH, and agitation speed of strain FM04 were 28∼30$^{\circ}C$, 5.0∼6.0, and 100 rpm, respectively. Starch was the best carbon source in the amylase production. Therefore, food wastes containing lots of starch were employed as the carbon source of the cultivation for the economical amylase production. 5.2 U/ml of amylase was obtained In the cultivation using 1 % (w/v) of food wastes. The amylase showed the highest activity at enzyme reaction conditions of 60$^{\circ}C$ and pH 4.5 and showed 90% of residual activity after the reaction at 50$^{\circ}C$ for 2 days. In the enzymatic hydrolysis reaction using 20% (w/v) of food wastes and 2.5 U/ml of amylase, 72.6 g/l of reducing sugar was obtained at the reaction condition of 50$^{\circ}C$, pH 4.5 for 2 days.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.770-773
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• 1999

To obtain the basic data for the improvement of flayer and color in salt-fermented anchovy (Engraulis japonicus) sauce and for the inhibition of non-soluble precipitates formation during storage, experiments were carried out on the changes of chemical properties by treatment with 1, 3, 5 and $7\%$ (w/v) of active carbon and filter aids such as active clay, $Al_2O_3$ diatomaceous earth, and celite. Deceleration rate were $32\~33\%$ in case of $5\%$ (w/v) active carbon or $5\%$ (w/v) active clay treatments, but deodoration effect was not expected in all treatments. The inhibition rate of non-soluble precipitates formation in me of $5\%$ (w/v) active clay, diatomaceous earth and $Al_2O_3$ treatments. was shown as $82\%,\;73\%$, and $70\%$, respectively.

• Journal of the Korean Geosynthetics Society
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• v.15 no.4
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• pp.89-96
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• 2016

Compressive axial behavior of the variable cross-section soft ground reinforced foundation is investigated from the field load test results at ${\bigcirc}{\bigcirc}$ construction site in Incheon city. Variable cross-section soft ground reinforced foundation is a type of partial-displacement pile formed by mixing bidding material with in situ soils to obtain a rigid and strong variable cross-section column in a relatively soft ground. The foundations are usually constructed as a group; however in this study, only single foundation was installed and tested under compressive axial load on foundation head. For the comparison of the variable cross-section soft ground reinforced foundation axial behavior, behavior of typical Pretensioned spun high strength concrete (PHC) pile constructed on a relatively soft ground near the surface was analyzed. It was concluded that variable cross-section soft ground reinforced foundation efficiently resists against axial load with sufficient stiffness and strength within a considerable range of axial load magnitude.