• 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.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.569-574
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• 1990

The influence of NaCl and pH on degradation of chicken breast muscle myofibrillar proteins by porcine leukocyte lysosomal proteinases was investigated. The degradation reactions were carried out at $38^{\circ}C$ for 24hours under different conditions. The degradation of myofibrillar proteins by leukocyte lysosomal enzymes at various pH values was limited to partial hydrolysis. Reactions at higher pH values resulted in lower molecular weight degradation products while reactions at lower pH resulted in higher molecular weight degradation products. When NaCl was added into the reaction mixture, enzyme activities of degradation were increased at all pH values studied, as evidenced by NPN-analysis and SDS-PAGE. More severe degradation was observed with higher salt concentration. The concentration of 0.5M NaCl in the reaction mixture gave more degradation of myosin heavy chain by enzyme than that of 0.1M NaCl.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.5
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• pp.430-438
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• 2008

Siberian spruce, found in the northern temperature and boreal regions of the earth, is usable biomass as fuels. In this study, parameters of thermochemical degradation by pyrolysis-liquefaction reaction of siberian spruce such as the effect of reaction temperature, reaction time and degradation products and energy yields were investigated. The liquid products from pyrolysis-liquefaction of siberian spruce contained various kinds of cyclicketones, cresols, dimethyl phenols and benzenediols. Combustion heating value of liquid products from pyrolysis-liquefaction conversion processes was in the range of $7,650{\sim}7,800cal/g$. The energy yield in pyrolysis-liquefaction of siberian spruce was as high as 69.5% after 40min of reaction at $400^{\circ}C$. The liquid products from the thermochemical conversion of siberian spruce could be used as high octane value fuels and fuel additives.

• Journal of the Korean Chemical Society
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• v.11 no.2
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• pp.70-76
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• 1967

Structural changes attending polyacrylonitrile(PAN) upon heating and treating with nucleophilic reagents have been studied for some time and a few authors have studied on the thermal degradation, particularly on the characterization of degradation products in PAN. It is the purpose of this paper to report the kinetic study on the thermal degradation above $250^{\circ}C$ and make some suggestions as to the degradation process and mechanism in PAN. The degradation process in PAN is considered that three reactions are combined in two steps. Random chain scission accompanying the naphthylidine-type ring formation is the first step and the degradation of naphthylidine-type ring occurred as the next step. The reactions in the first step are competitive so that the maximum weight loss on pyrolysis of PAN, under such a condition that the degradation of naphthylidine-type ring is negligible, is depended on the relative reaction rate of these two competitive reactions.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.685-694
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• 2016

In this study, the thermal degradation behavior of biomass during torrefaction was studied by thermogravimetric and byproduct gas analysis. Torrefaction temperature, time, and heating rate were $220{\sim}300^{\circ}C$, 110 min, and $10{\sim}30^{\circ}C/min$, respectively. The degradation rate of yellow poplar was 8.01~8.81% at $220^{\circ}C$ and 71.86~77.38% at $300^{\circ}C$ depending on heating rate. The degradation rate significantly increased at temperature over $240^{\circ}C$. On the other hand, degradation rate of larch was relatively low as 49.58~54.15% at $300^{\circ}C$. The activation energy of yellow poplar was 87.32~91.24 kJ/mol; these values did not significantly change with heating rate. The activation energy of larch was 83.85~91.60 kJ/mol. The major components of the gas generated during torrefaction were derived from hemicellulose. The component types and concentrations increased with torrefaction severity. High concentrations of furfural and acetic acid were detected during torrefaction of yellow poplar.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2000.11a
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• pp.160-160
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• 2000

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.572-578
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• 2013

Azotobacter vinelandii, a strict aerobic nitrogen-fixing bacterium, has been extensively studied with regard to the ability of $N_2$-fixation due to its high expression of nitrogenase and fast growth. Because nitrogenase can also reduce cyanide to ammonia and methane, cyanide degradation by A. vinelandii has been studied for the application in the bioremediation of cyanide-contaminated wastewater. Cyanide degradation by A. vinelandii in NFS (nitrogen-free sucrose) medium was examined in terms of cell growth and cyanide reduction, and the results were applied for cyanide-contaminated cassava mill wastewater. From the NFS medium study in the 300 ml flask, it was found that A. vinelandii in the early stationary growth phase could reduce cyanide more rapidly than the cells in the exponential growth phase, and 84.4% of cyanide was degraded in 66 h incubation upon addition of 3.0 mM of NaCN. The resting cells of A. vinelandii could also reduce cyanide concentration by 90.4% with 3.0 mM of NaCN in the large-scale (3 L) fermentation with the same incubation time. Finally, the optimized conditions were applied to the cassava mill wastewater bioremediation, and A. vinelandii was able to reduce the cyanide concentration by 69.7% after 66 h in the cassava mill wastewater containing 4.0 mM of NaCN in the 3 L fermenter. Related to cyanide degradation in the cassava mill wastewater, nitrogenase was the responsible enzyme, which was confirmed by methane production. These findings would be helpful to design a practical bioremediation system for the treatment of cyanide-contaminated wastewater.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.27-32
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• 1987

To isolate and identify degradation products of propanil in solution which propanil concentration was 2000ppm with a certain temperature, degradation products and pathway were investigated every 2 weeks for 12 weeks. Extracted mixture was developed with benzene on TLC plate, and Rf values of isolated DCA and TCAB were 0.65 and 0.94 respectively. At the GC analysis, propanil and its degradation products could seperate at the column temperature $200^{\circ}C$, but in order to more good resolution, the column temperature of DCA and TCAB was $140^{\circ}C$ and $250^{\circ}C$ respectively. Functional group of OCA was determined by IR spectrum $3400cm^{-1}$ and $800cm^{-1}$. Proton peaks of OCA were NMR spectrum $6.7{\delta}$ and $3.7{\delta}$. As the results, the major degradation products of propanil in solution were seperated on TLC plate, and thus identified by the analysis of GC, IR and NMR. Proposed degradation pathway of propanil in solution was from DCA to TCAB.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.1
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• pp.54-63
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• 2010

Recently, as the function of largest supplier of biomass for "low carbon green growth", the necessity for systematic management of afforestation areas is emphasizing. The forestation of seedling, besides the afforestation cost itself, is required some additional follow-up management costs, like mowing and fertilizing of forestation area, and removal of bindweed. The mulching mat for afforestation seedlings is available for rooting of little seedlings as well as initial forestation expenses. Mulching technique is also used to control soil temperature and moisture by covering the surface of ground. In this study, the paper based-mulching film coated with biodegradable polymer and functional additive was specially produced using laboratory bar coater, and analyzed for its degradable behavior. Coating colors were prepared by dissolving PE (polyester) 80 % and PLA(polylactic acid) 20 % in chloroform and finally applied to handsheet prepared by preceding study conditions. Base paper and polymer-coated paper were artificially aged by 2 kinds of degradation methods, which are soil degradation by microorganism and light degradation by 257 nm UV wavelengths. Strength property, oxidation index and morphological property were evaluated by reduction rates of tensile strength, FTIR spectra ratio of carboxyl and carbonyl group and SEM micrograph. As these results, polymer coated-paper was superior to base paper in degradation behaviors, having results with lower reduction rate of strength properties.

• Korean Journal of Agricultural Science
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• v.10 no.1
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• pp.146-155
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• 1983

Fundamental study was carried out to elucidate the mechanisms of biological degradation of dyestuff in environments. A few bacterial strains which were capable of degrading amarnath were obtained from soil through an extensive screening program and identified by microbiolological properties. Conditions for bacterial growth and amaranth degradation were characterized and optimized, and the degradation products were identified. The results were as follows. 1. The most active strain A12-1 to be capable of degradation of amaranth was identified as Pseudomonas sp. 2. Optimal conditions for growth of the strain A12-1 were:$35^{\circ}C$ and pH 7.5, and growth was markedly increaesd by aeration. 3. Degradation of amaranth by the strain was accessed under similiar conditions for growth, however significantly inhibited when the culture was aerated. 4. Both bacterial growth and amaranth degradation were gradually decreased with increased concentration of amaranth in the culture. 5. Reaction of the crude enzyme from the strain A12-1 was optimal at $35^{\circ}C$ and pH 7.5 for degrading amaranth. 6. Sodium naphthionate and R-amino salt were found to be the products of amaranth degradation by the strain A12-1.