• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.331-336
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• 1991

In order to utilize natural cellulosic materials as a fermentative substrate, saccharification of a various kind of native cellulosic materials was performed by using cellulase from the isolated strain, Pseudomonas sp. LBC-505 which potently produced cellulase complex and xylanase. Cellulase complex production was repressed by the low concentration of glucose, induced by cellulosic compounds such as CMC, wheat bran and rice straw et al. and showed to be highest on the PY-CMC medium containing 5% (w/v) wheat bran instead of CMC. Optimal temperature for enzyme reactions of CMCase and xylanase was $50^{\circ}C$, and $55^{\circ}C$ for $\beta$-glucosidase. Optimal pH for these enzyme reaction was 6.6. Rate of saccharification for natural cellulose was low by the treatment of crude enzyme. Among their substrates, rice straw was the most effective substrate of enzymatic reaction in this work. After treating rice straw with 5% (v/v) HC1 and hydrolysing with crude enzyme, rate of saccharification was 18.4% (w/w) on dry substrate. Sugars of cellulosic hydrolyzate mainly contained glucose, xylose and cellobiose.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2011.04a
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• pp.81-91
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• 2011

Current fuel ethanol research and development deals with process engineering trends for improving biotechnological production of ethanol. Recently, a large amount of studies regarding the utilization of lignocellulosic biomass as a good feedstock for producing fuel ethanol is being carried out worldwide. The plant biomass is mainly composed of cellulose, hemicellulose and lignin. The main challenge in the conversion of biomass into ethanol is the complex, rigid and harsh structures which require efficient process and cost effective to break down. The isolation of microorganisms is one of the means for obtaining enzymes with properties suitable for industrial applications. For these reasons, crude cultures containing cellulosic biomass degrading microorganisms were isolated from rice field soil, cow farm soil and rotten rice straw from cow farm. Carboxymethyl cellulose (CMC), xylan and Avicel (microcrystalline cellulose) degradation zone of clearance on agar platefrom rice field soil resulted approximately at 25 mm, 24 mm and 22 mm respectively. As for cow farm soil, CMC, xylan and Avicel degradation clearancezone on agar plate resulted around at 24mm, 23mm and 21 mm respectively. Rotten rice straw from cow farm also resulted for CMC, xylan and Avicel degradation zone almost at 24 mm, 23 mm and 22 mm respectively. The objective of this study is to isolatebiomass degrading microbial strains having good efficiency in cellulose hydrolysis and observed the effects of different substrates (CMC, xylan and Avicel) on the production of cellulase enzymes (endo-glucanase, exo-glucanase, cellobiase, xylanase and avicelase) for producing low cost biofuel from cellulosic materials.

• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.190-195
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• 2006

The critical micelle concentrations (CMC) and the counter ion binding constants (B) in a micellar state of the mixed surfactant systems of sodium dodecylbenzenesulfonate (DBS) with polyoxyethylene(4) lauryl ether (Brij 30) in water were determined as a function of 1 (the overall mole fraction of DBS) by the use of electric conductivity method and surface tensiometer method from 288 K to 308 K. Various thermodynamic parameters (Smo, Hmo, and Gmo) for the micellization of DBS/Brij 30 mixtures were calculated and analyzed from the temperature dependence of CMC values. The measured values of Gomare all negative but the values of Smo are positive in the whole measured temperature region. On the other hand, the values of Hmo are positive or negative, depending on the measured temperature and 1.

• Journal of Energy Engineering
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• v.18 no.2
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• pp.87-92
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• 2009

An experimental investigation is conducted to study a 2-phase vertically upward hydraulic transport of solid particles by water and non-Newtonian fluids in a slim hole concentric annulus with rotation of the inner cylinder. Rheology of particulate suspensions in viscoelastic fluids is of importance in many applications such as particle removal from surfaces, transport of proppants in fractured reservoir and cleaning of drilling holes, etc. In this study, a clear acrylic pipe was used in order to observe the movement of solid particles. Annular velocities varied from 0.3 m/s to 2.0 m/s. The mud systems included fresh water and CMC solutions. Main parameters considered in the study were inner-pipe rotation speed, fluid flow regime and particle injection rate. A particle rising velocity and pressure drop in annulus have been measured for fully developed flows of water and of aqueous solutions. For both water and 0.2% CMC solutions, the higher the concentration of the solid particles is, the larger the pressure gradients become.

• Analytical Science and Technology
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• v.8 no.2
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• pp.107-116
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• 1995

The critical micelle concentration(CMC) of CTAB was determined with changes in absorbance at 202nm band of 4-biphenyl acetate($BPA^-$). With $BPA^-$ as a probe, the effect of temperature on CMC of CTAB has been observed between $30^{\circ}C{\sim}70^{\circ}C$. In this range of temperature the values of CMC are $1.18{\times}10^{-4}{\sim}2.02{\times}10^{-4}M$. The free energy(${\Delta}G^{\circ}m$) and enthalpy(${\Delta}H^{\circ}m$)for the micellization of CTAB was negative and the entropy(${\Delta}S^{\circ}m$) was a large positive value. The micellization of CTAB is considered as a spontaneous process and to involve a phase transition. The orientational binding of 4-biphenyl acetate anion to the CTAB micelle interface has been studied with $300MHz\;H^1-NMR$ data. The change in chemical shift of proton in CTAB as well as those of the protons in $BPA^-$ have been investigated by increasing the mole fraction of the anion in the mixed solutions. The changes in chemical shift with increasing mole fraction of anion($BPA^-$) indicate the formation of mixed micelle between CTAB and $BPA^-$. The changes in chemical shifts of methylene protons in CTAB, demonstrate the penetration of $BPA^-$ into the palisade layer of the CTAB micelle.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.5
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• pp.333-341
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• 2001

The Compost-decomposing-bacteria was isolated from livestock compost containing sawdust. The isolated bacteria was identified as Bacillus subtilis LYH201 by the method of the composition of the fatty acid with MIDI system and Bergey's manual. Cloning of CMCase encoding gene was accompanied by shotgun method. The pLK100 have yellow activity ring on CMC medium, that was carried 2.2 kb insert DNA in pBluescript II $SK^+$ vector, named BglC gene. The BglC was very similar to Pectobacterium carotovorum Gun_CLOAB(P15704) with score of 57% identity and 71% homology over 508 aa. The BglC was measured molecular weight 56 kDa by CMC-SDS-PAGE. Optimum cellulase activity Bacillus subtilis LYH201 was temperature $50^{\circ}C$ and pH 7.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.28-32
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• 1992

The critical micelle concentration(CMC) values of Dodecylpyridinium bromide(DoPB) were determined by an electric conductivity method at 1${\sim}$2000 bars and $25^{\circ}C$. The CMC of DoPB increases with the addition of urea in the whole pressure region studied, and the CMC increases with an increase of the pressure in the low-pressure region, while in the high-pressure region the CMC decreases. The partial molar volume change $({\Delta}V^m_o)$ on micellization was also investigated in some urea aqueous solutions. The change $({\Delta}V^m_o)$ was reduced by the addition of urea. The results suggest that the "iceberg" structure of water around the hydrocarbon chain of the monomeric surfactant is effectively broken down by urea.

• Clean Technology
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• v.13 no.3
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• pp.201-207
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• 2007

Carboxymethylcellulose (CMC), which is water-soluble at room temperature, was synthesized from cellulose in this study. Experimental parameters included reaction temperature, time, concentration of NaOH, and monochloroacetic acid (MCA). In mercerization and etherification, solubility and degree of substitution (DS) increased when NaOH (or MCA) concentration increased and maximum solubility and DS were achieved when NaOH or MCA was 30%. The effect of MCA concentrations on the DS was larger than that of the NaOH concentration. Tensile strength of the CMC was decreased by the increases of reaction time, reagent concentration and reaction temperature. Tensile strength also decreased by NaOH and MCA. However, low decrease of tensile strength was observed in near neutral region.

• The Korean Journal of Mycology
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• v.17 no.2
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• pp.57-65
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• 1989

The effect of various cellulosic and hemicellulosic substrates on the induction of cellulase and xylanase complexes in Aapergillus nidulans was investigated. The most efficient substrates for the induction of cellulase and xylanase complexes were carboxymethylcellulose for endoglucanase, cellobiose for ${\beta}-glucosidase$, and xylan for endoxylanase and ${\beta}-xylosidase$, respectively. However, the mixtures of these substrates, especially CMC-xylan and CMC-xylan-laminarin mixture, were much more effective not only for the enhancement of the biosynthesis of all the cellulase and xylanase complexes but also for the balanced production of these enzyme components than individual substrate. The polyacrylamide gel electrophoresis followed by activity staining showed the variation in the patterns and relative intensity of ${\beta}-glucosidase$, endoglucanase and endoxylanase components in individual enzyme preparations from A. nidulans cultures grown on different substrates. These results suggest that the biosynthesis is of cellulase and xylanase systems in A. nidulans is regulated in coordination at the level of induction.

• The Journal of Korean Association of Computer Education
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• v.3 no.1
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• pp.31-41
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• 2000

Since the use of computer-mediated communication(CMC) systems has been steadily increasing in the teaching and learning environments, this study attempted to describe some of instructional strategies which can be employed as a medium of cooperative learning. One of the best way to conduct network-assisted instruction is to embed such a medium into cooperative learning. Network-assisted cooperative learning maximizes students' own learning and each other's learning using CMC, in which students can actively participate in their learning processes. The characteristics of CMC-transmission and search of information, interactivity, time and place independence-assist and enhance cooperative learning. In this study, the instructional strategies for cooperative learning via CMC are suggested as following: (1) choose the instructional goals, (2) structure positive interdependence, (3) select guidelines for grouping, (4) train cooperative skills to students, (5) set up the environments such as electronic bulletin-board, and (6) develop assessment tools. Finally, this study suggests that potentials of network-assisted cooperative learning can be realized by providing environments and thinking tools for cooperative learning. Appropriate theory and practice need to be followed up to support the cooperative learning systems.