• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.406-411
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• 2008

This study was conducted to examine the quality enhancement of fermented soybean pastes (cheonggukjang) using microorganisms with high enzyme activities and proper experimental design. The microorganisms for soybean paste fermentation were selected from a specific area of Gyeonggi and were idenlified by 16S rDNA sequence analysis. To prepare the cheonggukjang, an optimum mixing ratio of selected microorganisms was determined using contour plots and numerical optimization methods. A total of 39 microorganisms were isolated from the soybean paste, consisting primarily of Bacillus subtilis and Bacillus licheniformis, and no mold was found. Three microorganisms showing high enzyme activities were selected and used to formulate an optimum mixing ratio for cheonggukjang preparation. Based on levels of amino-nitrogen, ammonium-nitrogen, antioxidant activity values, and sensory preference results, the optimum mixing ratio of 50% of Bacillus sp. SC-1 and 50% SC-3 was suggested for the manufacture of high quality of cheonggukjang.

• Journal of Soil and Groundwater Environment
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• v.8 no.3
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• pp.61-73
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• 2003

A model describing the distribution of contaminants in soil/water systems for the application of soil-washing technology using surfactant was developed. The model simulation was conducted for screening the best surfactant, evaluating the effect of water dose, and optimizing soil-washing methodology. Naphthalene, phenanthrene, and pyrene as target compounds and Triton X-l00, Tergitol NP-10, Igepal CA-720, and Brij 30 as surfactants were used in the model simulations. The washing efficiency was not greatly enhanced by increasing water dose with the same total surfactant dose. The approach of successive washings was more efficient than a single washing with the same amount of water and surfactant. Equal allotment of the amount of water and surfactant was the best condition for the successive washings. The model can be applied for the optimal design of the soil washing process without extra experimental efforts.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.49-54
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• 2004

Biotransformation process using microorganisms was examined to improve the bioconversion rate for the production of sotolon from the raw material. First, the extraction condition was optimized with regard to solvent type and pretreatment conditions. Dichloromethane was selected as a suitable solvent for the extraction of sotolon and sotolon-related compounds. Second, various microorganisms such as lactic acid-producing bacteria, yeast and fungi were tested for the biotransformation. Among the tested microbes, Agaricus blazei showed the highest conversion rate. Additives including amino acids, salts, and organic acids were investigated to test their effects on bioconversion. When the solution was added by isoleucine, ${\alpha}-ketoglutaric\;acid$, ascorbate, and $FeSO_4$ and later incubated by culture broth containing the mycelium of Agaricus blazei, the sotolon content increased up to about 77 times as compared to that of the raw material.

• Resources Recycling
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• v.19 no.4
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• pp.51-57
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• 2010

As a recycling of Si sludge from Si wafer process, a Si-SiC-CuO-C composite material was synthesized and investigated as an anode material for lithium batteries. The Si sludge consisted of Si, SiC, machine oil, and metallic impurities. The oil and metal impurities was removed by organic washing, magnetic separation, and acid washing. The Si-SiC-CuO-C composite from the recovered Si-SiC mixture was prepared by high-energy mechanical milling. According to the electrochemical tests such as charge-discharge capacity and cycling behavior, it showed the improved cycle performance. The SiC and CuO-related phases were presumed to restrain the volume expansion of the anode and Fe, however, should be removed below 10 ppm prior to synthesis of the composite because it caused the capacity loss of the active material itself.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5792-5799
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• 2013

The purpose of this study was the Application of the HACCP (Hazard Analysis Critical Control Point) system to Korean Rice Cakes. Main ingredients of rice cakes, work facilities and workers were provided from KB company located in Seogye-dong Yongsan-gu, Seoul between September 12, 2012 and February 13, 2013. The manufacturing process chart was prepared by referring to the manufacturing process of rice cake manufacturers in general. As a result of this study, the microbiological hazard analysis on raw materials and finished products of rice cakes showed safe result. However, microorganism test on the manufacturing environment and workers suggested that microbiological hazard should be reduced through systematic cleaning and disinfection, accompanied by improved personal hygienes based on hygienic education on workers and management of microorganisms in the air.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.137-144
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• 2014

The PHC pile utilizing the air-cooled blast-furnace slag as coarse aggregate was studied. This research was progressed with the range from the indoor mixing design evaluation into the actual goods production. The physical properties of the PHC pile are determined to satisfy through the appropriate mixing design adjustments. However, it should eliminate the aggregates including CaO and MgO in SG when it utilize in an AC (autoclave) type manufacturing process. It satisfied the bending moment, shear strength, and compressive strength of KS F 4306 except the surface states of the pile.

• Journal of the Korean GEO-environmental Society
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• v.16 no.5
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• pp.27-33
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• 2015

Manganese in sludge precipitated during water treatment might be soluble again in effluent from sludge thickener. If that happens, the manganese concentration of effluent from water treatment plant will exceed the limit for clean reservation. In this study the influence of pH on Mn concentration of effluent from sludge thickener of water treatment plant was investigated. When the pHs of sludge solutions increased with alkaline materials such as NaOH, KOH, CaO, $Ca(OH)_2$, $CaCO_3$, the Mn concentrations of sludge solutions decreased under the limit. The Mn concentration of effluent from sludge thickener could be controlled with waste limestones from beneficiation process at limestone mine as an alkaline material.

• Resources Recycling
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• v.24 no.4
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• pp.38-49
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• 2015

The importance of recycling came to the fore by increasing of waste electrical and electronic equipment(WEEE) generation. Small WEEE recycling in particular represents a big challenge in Korea because it has various items and components. Main materials of small WEEE are typically well known for metals (copper, iron, aluminum, etc.), PCBs and plastics. Not only Korea but also overseas, the laws for small WEEE were in effect in order to recycle effectively, but the technology is not catched up with the regulation which has to recycle an allocated account of WEEE. In addition, recycling technologies and processes for small WEEE are not developed enough to recycling center properly. In that sense, if we develope the recycling process, have not only technology competitiveness but also resource conservation, improving the environment and economic profits. Therefore, through the analysis of economic value of recycled small WEEE, and current technologies both domestically and internationally, we design conceptual recycling process of small WEEE, and consider the way forward.

• Journal of IKEEE
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• v.19 no.4
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• pp.486-490
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• 2015

Sensitivity characteristics of temperature sensor with $Bi_2Mg_{2/3}Nb_{4/3}O_7$ (BMNO) layer were investigated with low frequency noise measurement. Temperature sensor with BMNO layer had high reliability and high sensitivity comparing with conventional MOS type temperature sensor. Annealing temperature variation effects with $600^{\circ}C$, $700^{\circ}C$ and $800^{\circ}C$ were measured and analyzed. Annealing temperature determines trap distribution and $700^{\circ}C$ annealing sample has different pattern comparing with other samples. Results of low frequency noise can offer the design guide of temperature sensor performance.

• Land and Housing Review
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• v.14 no.1
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• pp.135-144
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• 2023

LH Corporation uses the construction waste disposal fee standard, of which the model was developed a long time ago. Therefore, this model is problematic because it needs to reflect waste treatment facilities' technological development and environmental conditions. In this study, the estimated manpower and costs required for the process operation of waste treatment facilities were analyzed, followed by the proposed estimation criteria. This improved standard model can be used as a cost calculation standard for the recycling and treatment of construction waste in public institutions. The study also suggests that an increase in waste treatment costs is needed.