• Elastomers and Composites
• /
• v.31 no.2
• /
• pp.122-129
• /
• 1996

The Thermal decomposition of the ${\alpha}-Cellulose$ and NaCl was studied using a thermal analysis technique in the steam of nitrogen gas with 30ml/min at various heating ranges from 4 to $20^{\circ}C/min$. The Derivative and Integral method used to be obtained values of activation energy of decomposition reaction. 1. The values of activation energy evaluated by Derivative and Intergral method were consistent with each other very well. 2. The maximum value of heat of decomposition evalated by DSC method was ${\alpha}-Cellulose/NaCl= 90/10$. 3. The thermogravimetric trace curve agreed with the theoretical equation.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.18 no.4
• /
• pp.345-350
• /
• 1998

In order to evaluate the feed value of rice straw as influenced by ripening stage, and to determine the effects of chemical treatments and ensiling on its feeding value, in situ studies using a rumen fistulated Korean cow nylon bag technique, and digestion trials with sheep were conducted. Experiments were conducted at the Experimental Farms, Woosuk University, Wanju in 1998. The results obtained are summarized as follows; 1. The contents of crude protein and crude fat were decreased(P<0.05), while those of crude fiber and crude ash were increased as the ripening of rice straw progressed. The content of NDF was not affected by the ripening stage. After the yellow stage hemicellulose was remarkably decreased while cellulose and lignin were increased. 2. Degradation of rice straw NDF in the rumen was most rapid when at the heading stage, but degradation of straws after the milky stage were similar each other. Degradation of rice straw ADF, on the other hand, did not show any difference with advancing ripening stage. In Conclusion, the change of chemical composition and degradation rate of rice straw in the rumen under the different ripening stage, it can be concluded that the lignification of rice straw was accelerated after the heading stage.

• Tribology and Lubricants
• /
• v.35 no.3
• /
• pp.151-157
• /
• 2019

Insulated oil degradation produces charged by-products, such as acids and hydro-peroxides, which tend to reduce the insulating properties of the oil. In this study, UV-vis spectroscopy measurement technology is developed and experimentally compared with other measurement methods, such as the titration method and IR spectroscopy, to validate its ability to monitor the degradation of electrical insulating paper. The degradation characteristics of the insulating paper are appropriately represented through various types of measurement methods, such as the Tan (delta) method, $CO_2$ gas production measurement, the titration method, and IR spectroscopy. The results are demonstrated to be well comparable to a change in the fluorescence emission ratio (FER), which is defined as the shift in fluorescence intensity in the measured wavelength range, and also to the chromatic ratio, which is defined as a color shift to longer wavelength ranges. The results also show that, by using UV-vis spectroscopy, it is possible to detect the degradation of the insulating paper. This study suggests that UV-vis spectroscopy can be applied as an alternative to high-performance liquid chromatography, which is the internationally recognized measurement technology for cellulose paper degradation. The FER detector is also verified to be useful as an effective condition-monitoring device for power transformers.

• Textile Coloration and Finishing
• /
• v.30 no.4
• /
• pp.245-255
• /
• 2018

In this study, cotton fabrics were coated with $TiO_2$ nanoparticles using 3-mercaptopropyltrimethoxysilane(3-MPTMS), which is highly reactive to cotton fabrics, as a medium, and the characteristics, antimicrobial properties, and photodegradation properties of the fibers were measured. The manufacturing process is as follows. (1) 3-MPTMS was added to isopropanol, and $TiO_2$ colloid was added to the mixture to prepare a solution. (2) Cellulose fibers were immersed in the prepared $3-MPTMS/TiO_2$ solution, stirred for 90 minutes at $45^{\circ}C$ in a constant temperature water bath, and dried thereafter. In order to identify the morphology of the cellulose fibers coated with $TiO_2$ nanoparticles, the surface was observed with a scanning electron microscope(SEM), and SEM-EDS was measured to identify the adhesion of $TiO_2$ nanoparticles. The SEM images showed $TiO_2$ nanoparticle and 3-MPTMS coated layers on the fibers and it was identified that $TiO_2$ nanoparticles were attached to the cellulose fibers. The antimicrobial activity of $3-MPTMS/TiO_2$-treated cotton fabrics was measured using a bacterial reduction method. $3-MPTMS/TiO_2$ cellulose fibers which was irradiated by ultra violet light, showed antimicrobial activity against Escherichia coli(ATCC 43895) and Staphylococcus aureus(ATCCBAA-1707) unlike unirradiated fibers. The cellulose fibers were stained with methylene blue and the photodegradation performance of the stained fabrics was analyzed. The stained fabrics showed high degradation performance with photolytic reactions of $TiO_2$ nanoparticles.

• Journal of the Korean Society of Tobacco Science
• /
• v.27 no.1 s.53
• /
• pp.75-82
• /
• 2005

This work investigated biodegradability for the cellulose acetate, carbon dual, paper and web used to cigarette filter materials by soil test. Also, because of demanded a lot of the time and effort in case of soil test, the possibility of biodegradation by enzyme was studied. The evaluation of degradation for the filter materials by soil test was examined with the naked eye, electron microscopy and weight loss. The biodegradability according to the filter materials was represented in the order of paper > web > carbon dual > cellulose acetate without relating to the evaluation methods. Experiment of biodegradability by the cellulase(E C 3.2.1.4, Trichoderma viride) among the several biodegradability enzymes was demanded reaction time of the $5\~10$ hours and represented the same result with that of soil test.

• Asian-Australasian Journal of Animal Sciences
• /
• v.7 no.1
• /
• pp.41-48
• /
• 1994

This experiment was carried out in order to evaluate the chemical composition and rumen degradation characteristics of Italian ryegrass harvested at three different growth stages, i,e. pre-blooming, early-blooming and late-blooming. Degradation values were obtained by incubation of the samples using the nylon bag technique on the rumen of sheep fed a normal diet (Timothy hay with 200 g/d concentrate per head) for 12, 24, 36, 48 and 72 hours, respectively. Neutral detergent fiver (NDF) content was highest at late-blooming (64.4%) while no difference was found among the pre-blooming and early-blooming (49.4% vs 48.3%). However, acid detergent fiber (ADF) content markedly increased from 30.0% at pre-blooming to 35.4% and 46.4% at early-blooming and late-blooming, respectively. Lignin and silica contents also increased as advancing maturity of the grass, Rumen degradation of dry matter (DM) significantly reduced (p < 0.05) as advancing maturity of the grass. Ruman degradation cellulose and ADF at pre-blooming were significantly higher (p < 0.05) than those of early-blooming and late-blooming. However, no significant differences were observed among the early-blooming and late-blooming. With advancing maturity, rumen degradation of NDF and hemicellulose significantly reduced (p < 0.05) at the incubation times.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.14 no.4
• /
• pp.141-150
• /
• 2006

To develop the microbial agents for the environmentally-friendly treatment and recycling of food waste, useful microorganisms, which showed higher degradation activities to various organic compounds and possessed flocculating activities, were isolated from the earthworm. One of the isolated strains, named JS-01, was further selected due to its higher flocculating activity against 0.5% Kaolin clay. JS-01 was identified as Bacillus pumilus sp. by 16s rDNA analysis. The optimal temperature and pH for the growth of JS-01 to express the flocculating activity was found to be at $37^{\circ}C$ in pH 7.0 of EPS broth medium. JS-01 also expressed good degrading activity against cellulose, which is one of the representative organic materials in food waste. We propose that JS-01 will be a good candidate for the efficient treatment of food waste and leachate due to the property to degrade cellulose and flocculating activity.

• Korean Journal of Microbiology
• /
• v.25 no.4
• /
• pp.293-303
• /
• 1987

A $C_{1}$ enriched cellulase fraction was separated from culture filtrate of anaerobic Clostridium thermocellum by hydroxyapatite column chromatography. The separated fraction showed strong synergistic action with $C_{x}$ component (endo-$\beta$-1, 4-glucanase) in digestion of crystalline cellulose, similar to the other aerobic cellulolytic microorganisms. Unlike the $C_{x}$ component the $C_{1}$ enriched fraction was rapidly inactivated by oxidation at the atmospheric condition. The enzyme activity was significantly enhanced by the addition of reducing agents, especially $\beta$-mercaptoethanol, which indicates that a $C_{1}$ component has a lot of sulfhydryl groups essential for the enzyme activity. The effect of metal ions on $C_{1}$ activity was also investigated. The $C_{1}$ fraction was found to be thermally stable compare to endo-$\beta$-1,4-glucanase. Optimal temperature and pH were found to be $60^{\circ}C$ and 6.0, respectively.

• KSBB Journal
• /
• v.7 no.1
• /
• pp.1-7
• /
• 1992

Degradation of structural carbohydrates has been observed in samples of sweet sorghum inoculated with either Clostridium cellulolyticum or Bacteroides succinogenes. However, conditions under which these rellulolytic organisms can compete effectively with lactic acid bacteria have not yet been determined. Degradation of cellulose by B. succinogenes was found not to be inhibited by either glucose or succinate.

• 보존과학연구
• /
• s.34
• /
• pp.20-29
• /
• 2013

Paper, textile and wood materials are mainly consisted of cellulose. Cellulose is high molecule and make up the strong crystalline structure by hydrogen bonds. In particular, the polymerization degree of cellulose are closely related to the strength of fiber, and the permanence. the useful life of fiber, also depends on the degradation of this substance. The viscosity of cellulose is considered to be an important indicator of fiber damage in high molecule polymers. The viscosity measurements with CED solution is used to measure the molecular weight and the degree of polymerization of cellulose. Cellulose viscosity of wood fibers is measured with TAPPI standard method T230. However, TAPPI standard method T230 is difficult to completely dissolving the cellulose of high molecular weight and large degree of polymerization, such as Korea traditional papers and fabrics made with mulberry, ramie, cotton fibers. In this study, The high viscosity of hanji and fabric was measured with TAPPI standard method T254. T254 method is that the cellulose specimen with the proper amount of weaker (0.167M CED) solution, and completely dissolved with the stronger (1.0M CED) solution. It was found that cellulose with high degree of polymerization was dissolved more easily in general CED method.