• Clean Technology
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• v.8 no.2
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• pp.85-92
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• 2002

Red mud is generated as a by-product during the production of aluminum hydroxide from bauxite ore. In this study the red mud coagulants were prepared by reacting 100 ml of 5 M $H_2SO_4$ solution with 10g of red mud at $85^{\circ}C$ or by reacting 100ml of 9M HCl solution with 10g of red mud at $25^{\circ}C$. The prepared red mud coagulants were tested for their coagulation performance of pollutants in the municipal and industrial wastewater. In addition, the coagulation performance was compared with that of a commercially available coagulant ($FeCl_3$). As a result, the red mud coagulants were found to have a good removal efficiency of pollutants in the municipal wastewater (turbidity, phosphate phosphorus) and in the plating wastewater (turbidity, $Pb^{2+}$, $Cd^{2+}$, $Cu^{2+}$, $Zn^{2+}$, $Cr^{3+}$). In the experiment to remove COD in the petrochemical wastewater, the COD removal efficiency by the red mud coagulants was a little poor, but it was better than that by $FeCl_3$.

• Clean Technology
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• v.12 no.4
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• pp.250-258
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• 2006

CFC compounds such as CFC-113 and 1,1,1-TCE, etc. have been used in various industries due to their excellent chemical stability, thermodynamic characteristics, non-inflammability and anti-corrosiveness. However, in oder to protect the earth environment, "the Montreal Protocol on substances that deplete the ozone layer" was adopted in 1989 for prevention of production and utilization of these CFC compounds and alternative cleaning agent have been required in the industry. The objective of this study is to develop non-aqueous cleaning agents that do not require major change of cleaning system, have excellent cleaning efficiency, are favorable to the environment, are harmless to the human body, and are not generated corrosive materials. In this work, non-aqueous cleaning agents have been formulated with glycol ether series and paraffinic hydrocarbon series with siloxane, and their physical properties and cleaning efficiencies were analyzed and compared with those of regulated materials. As a result of physical properties measurement of the formulated cleaning agents, it is expected that they may have good penetration ability into contaminated materials due to their properties with low density and low surface tension. Measurement of flash point and vapor pressure of the cleaning agents will be helpful for evaluation of their safety and working environment. The experimental results of cleaning flux, solder and grease by the formulated cleaning agents show that their cleaning abilities of soils were good and that there were no residues on the substance after cleaning. Therefore, alternative cleaning agents which have equivalent cleaning ability to regulating materials, good penetration ability and low hazard to human body, have been developed in this work.

• Journal of Life Science
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• v.22 no.11
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• pp.1545-1551
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• 2012

Authors report the glycoside hydrolase (GH) family 16 ${\beta}$-agarase from the strain of Agarivorans sp. JA-1, which authors previously stated as recombinant expression and characterization of GH-50 and GH-118 ${\beta}$-agarase. It comprised an open reading frame of 1,362 base pairs, which encodes a protein of 49,830 daltons consisting of 453 amino acid residues. Valuation of the total sequence showed that the enzyme has 98% nucleotide and 99% amino acid sequence similarities to those of GH-16 ${\beta}$-agarase from Pseudoalteromonas sp. CY24. The gene corresponding to a mature protein of 429 amino acids was recombinantly expressed in Escherichia coli, and the enzyme was purified to homogeneity by affinity chromatography. It showed maximal activity at $40^{\circ}C$ and pH 5.0, representing 67.6 units/mg. Thin layer chromatography revealed that mainly neoagarohexaose and neoagarotetraose were produced from agarose. The enzyme would be valuable for the industrial production of functional neoagarooligosaccharides.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.184-191
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• 2009

In the southern part of the Korean Peninsula including Jeju-island, the production amount of domestic cedar has increased gradually. However, their low qualities, expected to be caused by the low density and frequent knots, have restricted their practical utilization as the high value-added products. In this study, it is aimed to look for the new uses of domestic cedar and to examine the applicability for lamination lumbers of structural glued laminated timber (glulam). Above all, machine stress ratings for individual sawn lumbers confirmed that modulus of elasticity (MOE) of cedar lumber was lower than that of other common softwood species in Korea. On the other hand, cedar lumbers have enough stiffness to manufacture the structural glulam in accordance with Korean Industrial Standard (KS). The bonding strength and durability also met the KS limitation. Nevertheless, from the result of bending tests for cedar glulam, it was shown that the modulus of elasticity (MOE) did not meet the KS limitation. Therefore, it was concluded that additional researches were needed for reinforcing the stiffness of cedar glulam.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.907-912
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• 1997

Physicochemical characteristics of kochujang prepared with various raw materials, were investigated during 90 days of fermentation to obtain information for the industrial production of traditional kochujang. Reducing sugar contents of kochujang increased until 60 days but slightly decreased thereafter, showing highest value for malt added group. Ethanol contents increased after 45 days and were highest in Chinese matrimony vine group, followed by purple sweet potato and malt added groups. Amino nitrogen contents increased until the 45 to 60 days of fermentation, but ammonia nitrogen contents did not change significantly during fermentation. Amino and ammonia nitrogen contents were higher in soy sauce and Chinese matrimony vine added groups. Water activities decreased slightly during fermentation and purple sweet potato added group was lowest among the groups. Consistency of kochujang decreased until the middle of the aging but after that it increased. Consistency of purple sweet potato and Chinese matrimony vine added groups were remarkably higher than that of the others. The color values tended to decrease slightly during fermentation. Purple sweet potato kochujang was low in the lightness, redness and yellowness. Results of sensory evaluation showed garlic and malt added kochujang were more acceptable than purple sweet potato added kochujang due to more desirable taste and color.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.143-165
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• 2016

The amount of greenhouse gas emission reduction based on INDCs (Intended Nationally Determined Contributions) submitted to UN by each party is not sufficient to achieve the Paris Agreement's aim to "hold the increase in the global average temperature to well below $2^{\circ}C$ above pre-industrial levels and to pursue efforts to limit the temperature increase to $1.5^{\circ}C$" which was determined in the $21^{st}$ Conference of the Parties to the UNFCCC (COP 21). Accordingly, the emission reduction target of each party will be revised for the $2^{\circ}C$ goal. Among the several options to reduce the carbon emission, CCS (Carbon Capture and Storage) is a key option to curb $CO_2$ emissions from large emission sources such as fossil-based power plants, cement plants, and steel production plants. A large scale CCS demonstration projects utilizing $1^{st}$ generation $CO_2$ capture technologies are under way around the world. It is anticipated, however, that the deployment of those $1^{st}$ generation $CO_2$ capture technologies in great numbers without government support will be difficult due to the high capture cost and considerable increase of cost of electricity. To reduce the carbon capture cost, $2^{nd}$ and $3^{rd}$ generation technologies are under development in a pilot or a bench scale. In this paper, current status of large scale CCS demonstration projects and the $2^{nd}$ and $3^{rd}$ generation capture technologies are summarized. Novel capture technologies on wet scrubbing, dry sorbent, and oxygen combustion are explained in detail for all capture areas: post-combustion capture, pre-combustion capture, and new combustion technologies.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.285-288
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• 2016

Proteolytic enzymes perform hydrolysis of the peptide bonds in the protein and most commonly use in the industry. Pseudoxanthomonas sp. WD12 and WD32 were previously isolated as protease producers from a rotten wood sample. Here, we report the secreted proteolytic enzymes. The optimum enzyme reaction temperature for the secreted crude enzyme from the strain WD12 and WD32 were $50^{\circ}C$ at pH 9.0 and $45^{\circ}C$ at pH 8.0, respectively. The enzyme activities of both strains were increased by addition of KCl, NaCl, $CaCl_2$ or $MnSO_4$, and decreased by addition of $AgNO_3$, $CuSO_4$, $FeCl_3$ or $AlCl_3$. Secreted enzymes of both strains were most strongly inhibited by addition of $FeCl_3$ or $CuSO_4$. Taken together these results, WD12 could be a candidate strain of industrial alkaline protease production.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.390-399
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• 2012

Endoglucanase gene egIV was cloned from Trichoderma viride AS 3.3711, an important cellulose-producing fungus, by using an RT-PCR protocol. The egIV cDNA is 1,297 bp in length and contains a 1,035 bp open reading frame encoding a 344 amino acid protein with an estimated molecular mass of 35.5 kDa and isoelectronic point (pI) of 5.29. The expression of gene egIV in T. viride AS 3.3711 could be induced by sucrose, corn straw, carboxymethylcellulose (CMC), or microcrystalline cellulose, but especially by CMC. The transcripts of egIV were regulated under these substrates, but the expression level of the egIV gene could be inhibited by glucose and fructose. Three recombinant vectors, pYES2-xegIV, $pYES2M{\alpha}$-egIV, and $pYES2M{\alpha}$-xegIV, were constructed to express the egIV gene in Saccharomyces cerevisiae H158. The CMCase activity of yeast transformants $IpYES2M{\alpha}$-xegIV was higher than that of transformant IpYES2-xegIV or $IpYES2M{\alpha}$-egIV, with the highest activity of 0.13 U/ml at induction for 48 h, illustrating that the modified egIV gene could enhance CMCase activity and that $MF{\alpha}$ signal peptide from S. cerevisiae could regulate exogenous gene expression more effectively in S. cerevisiae. The recombinant EGIV enzyme was stable at pH 3.5 to 7.5 and temperature of $35^{\circ}C$ to $65^{\circ}C$. The optimal reaction condition for EGIV enzyme activity was at the temperature of $55^{\circ}C$, pH of 5.0, 0.75 mM $Ba^{2+}$, and using CMC as substrate. Under these conditions, the highest activity of EGIV enzyme in transformant $IpYES2M{\alpha}$-xegIV was 0.18 U/ml. These properties would provide technical parameters for utilizing cellulose in industrial bioethanol production.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.677-685
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• 2005

Life Cycle Assessment(LCA) and Design for Environment(DfE) method were applied to design the environmentally sound manufacturing process of f31k lift in this study. Not only external movement of LCA and DfE method in the legal and systemic phase, but also active researches of those in the development phase of case study and application to the industrial field, have been going on. In concretely, the manufacturing processes of the folk lift generating the most environmental impact were examined by applying LCA method, and the environmentally sound manufacturing process was designed by applying, DfE method to the processes. As the results of LCA, environmental impacts for the eco-toxicity and human toxicity of seven major environmental categories were in high value, and so be in the cutting & welding process and painting process among the manufacturing processes. High solid paints, increasing the solid content of the existing solvent paints used in painting process, were developed to reduce the environmental impacts generated in the painting process. By utilizing the high solid paints, about 20% of environmental impacts (as environmental index of LCA) could be reduced.

• Journal of the Korean institute of surface engineering
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• v.49 no.6
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• pp.513-520
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• 2016

Many surface protection methods have been developed to apply to constructional steels which have been used under severe corrosive environments. One of these methods, hot dip galvanizing is being widely used to the numerous constructional steels such as a guard rail of high way, various types of structural steel for manufacturing ship and for some other industrial fields etc.. Recently, the cost of zinc is getting higher and higher, thus, it is considered that improvement of hot dip galvanizing process to reduce the cost of production should be developed possibly. In this study, additives such as acid cleaning solution, $NH_4OH$, $Al(OH)_3$ and $H_2O_2$ were added to flux solution, and omission of water washing treatment after acid cleaning was investigated with some types of flux solutions added with some additives mentioned above. The decrement of pH by adding the acid cleaning solution could be controlled due to neutralization reaction with addition of $NH_4OH$. The flux solution added with both $NH_4OH$ and $Al(OH)_3$ exhibited nearly the same color and pH value as those of orignal flux solution with no added, and the sample dipped to the flux solution which was added with additives mentioned above indicated a relatively good corrosion resistance compared to other samples. However, the flux solution added with $NH_4OH$, $Al(OH)_3$ and $H_2O_2$ exhibited a different color, sediment and a bad corrosion resistance. Consequently, it is considered that omission of water washing treatment may be able to perform by adding optimum additives to the original flux solution.