• Textile Coloration and Finishing
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• v.3 no.4
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• pp.13-16
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• 1991

C.I. Reactive Blue 19에 대한 hydroxylethylsulfonyl type의 수용액에서의 용해성과 안정성을 조사한 결과 이온강력 0.15, pH 5.8과 9.2에서 초기의 용해도를 4시간 동안 유지했으며, 이온강력을 증가시키면 용해도의 단정성이 감소했다. 그러나 용액의 교반하면 안정성이 증가하여 이온강력 0.30에서 초기용해도가 하루 동안 유지되었다. 셀로판 필름을 원주형태의 롤로 만들어 확산과 흡착 거동을 조사한 결과 hydroxylethylsulfonyl type의 용액 농도가 증가하면 표면농도, $C_0$가 증가했으나 확산계수, D는 일정한 값을 유지했다. Bis(arylsulfonylethyl)ether type의 셀룰로우스와의 반응성은 vinylsulfonyl type에 대해 겉보기 반응속도가 1/6 정도였다.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.1-6
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• 1996

Cellulose fiber reinforced cement composites manufactured by the slurry-dewatering process have found broad applications in thin cement products as replacement for asbestos cement. This paper focuses on the durability characteristics of these composites under different aging conditions. The effects of wetting-drying and freezing-thaw cycles, carbonation, and exposure to hot and humid environments on the structure and properties of cellulose fiber-cement composites were investigated. The predominant mechanisms of aging in the composites were identified through investigation of structure-property relationships. Measures to control these aging mechanisms were diversed and evaluated. Refined cellulose fiber-cement composites are shown to possess excellent durability characteristics under the effects of various aging processes.

• The Korean Journal of Rheology
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• v.10 no.1
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• pp.44-49
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• 1998

셀룰로오스/N-methyl morpholine N-oxide(NMMO)용액에 있어서 셀룰로오스의 분 자량 및 농도, 그리고 NMMO의 수화도가 유변학적 특성에 미치는 영향을 고찰하였다. 12wt%의 경우 NMMO의 수화도가 감소할수록 더 높은 온도에서 lower Newtonian 흐름영 역이 사라졌다. 15wt%에서는 측정된 전단영역에서 lower Newtonian 유동영역의 관찰되지 않았다. 동일한 농도에서 NMMO의 수화도가 감소할수록 점도가 증가하였으나 중량평균중 합도가 940인셀룰로오스/NMMO 용액의 경우 9$0^{\circ}C$에서 점도가 오히려 낮아졌다. 뿐만아니 라 이온도에서 power-law의 급작스런 감소도 나타낫다. NMMO의 수화도가 클수록 제1법 선응력차나 연신점도에 대한 온도의 영향이 증가하였다.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.112-117
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• 2000

Food waste is the main source of decay, odors and leachate in collection, transportation and landfill due to the high volatile solids (VS) and moisture content. Acidogenic fermentation of food waste is affected by the fermentation constraints including the biodegradability of substrate and the degrading capability of microorganisms. The biodegradability of food waste is mainly related to cellulosic materials, which are hardly degraded and comprise about 50% of food waste. The efficient and economical method of improving hydrolysis is, therefore, to apply microorganisms with increased cellulose-degrading capability. In this experiment, rumen microorganisms were inoculated to improve the low efficiency of acidogenic fermentation, and then compared with that of mesophilic acidogens. The fermentation of food waste in a leaching bed reactor employing rumen microorganisms resulted in the enhanced acidification (71.2% at $3.0d^{-1}$), which was higher than that (59.8% at $4.5d^{-1}$) employing mesophilic acidogens. This indicated that Rumen microorganisms had an enhanced waste-degrading capability.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.118-123
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• 2000

Food waste results in various problems such as decay, odors and leachate in collection, transportation and landfill due to the high volatile solids and moisture content. Acidogenic fermentation of food waste is influenced by the environmental conditions such as pH, retention time, etc. Each component of food waste is degraded under the different environmental conditions. Starch, cellulose and protein have their own optimum pHs and retention times for degradation. The degradation of starch increases at low pH, cellulose with increasing retention time, and protein with increasing retention time as well as approaching neutral pH. These mean that the degradation of food waste can be enhanced by adjusting the environmental conditions of acidogenic fermentation. The efficiency of acidification increased from 71.2 to 81.1% by controlling dilution(D) rate from 3.0 to $1.0d^{-1}$ depending on the state of the fermentation. The main component of the acidified product was shifted from butyric to acetic acid, indicating that the increase of acidification was mainly caused by the enhanced degradation of vegetables and meats.

• Journal of the Korea Concrete Institute
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• v.22 no.4
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• pp.473-479
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• 2010

The objective of the paper is to experimentally investigate the effect of commercially avaliable fiber types such as polypropylene (PP), nylon (NY), polyvinyl alcohol (PVA) and cellulose (CL) on the engineering properties of concrete for pavement application. The results, showed the fluidity tends to decrease with fibers addition compared to that of plain concrete. As for the effect of fiber types on fluidity loss, use of NY appear to give the most favorable results among all of the fiber types investigated in this study while the effect of the fibers on air content was negligible. For the properties of hardened concrete, compressive and flexural strengths increased with fibers compared to plain concrete. The contribution of NY fibers to strength was the highest followed in the order by NY, PVA, PP, and CL. However, in the case of the splitting tensile strength, its values were increased with NY and PP only. For porosity based on MIP(mercury intrusion penetration) method, the number of around 1 was observed when NY was mixed resulting in increased cumulated amounts of porosity compared with that of plain mix. Thus, based on the consideration of fluidity and strength it was found that the addition of NY fiber showed the optimal results under the conditions applied in this study.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.443-451
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• 2020

In this study, the physico-chemical properties and pyrolysis kinetics of livestock mature solid fuel were investigated to know its feasibility as a fuel. Ultimate and proximate analysis results showed that livestock mature solid fuel has high contents of volatile matter (64.94%), carbon (44.35%), and hydrogen (5.54%). The low heating value of livestock mature solid fuel (3880 kcal/kg) was also higher than the standard requirement of solid fuel (3000 kcal/kg). Thermogravimetic analysis results indicated that livestock mature solid fuel has three decomposition temperature regions. The first temperature zone (130~330 ℃) was consisted with the vaporization of extracts and the decomposition of hemicellulose and cellulose. The second (330~480 ℃) and third (550~800 ℃) temperature regions were derived from the decomposition of lignin and additional decomposition of carbonaceous materials, respectively. The activation energy derived from model free kinetic analysis results including Friedman, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) methods for the pyrolysis of livestock mature solid fuel was in the range of 173.98 to 525.79 kJ/mol with a conversion rate of 0.1 to 0.9. In particular, the activation energy increased largely at the higher conversion than 0.6. The kinetic analysis using a curve-fitting method suggested that livestock mature solid fuel was decomposed via a multi-step reaction which can be divided into five decomposition steps.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.77-81
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• 2007

Pentacene was dissolved in N-methyspyrrolidone (NMP) and mixed with poly(3,4-ethylenedioxythiophene), poly(styrenesulfonate) (PEDOT:PSS). The solution color changed from deep purple to intense yellow. As the dissolution time increased, visible absorption decreased and ultraviolet (UV) absorption increased. PEDOT:PSS or Pentacene-PEDOT:PSS was spin-coated to control the layer thickness. Three-layered Schottky diodes consisting of Al, PEDOT:PSS or PEDOT:PSS-pentacene, and Au with thickness of 300nm, respectively, were fabricated. The current densities of $4.8{\mu}A/cm^2$ at 2.5MV/m and $660{\mu}A/cm^2$ at 1.9MV/m were obtained for the Au/PEDOT:PSS/Al and Au/Pentacene-PEDOT:PSS/Al Schottky diodes, respectively. The current density of the Schottky diode was enhanced by about two orders of magnitude by doping pentacene to PEDOT:PSS.

• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.134-138
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• 2000

Extensive screening for cellulose-producing bacteria was done using differential media. Fifty seven strains were isolated totally from the fruits and the vinegar, respectively; the isolate A9 strain from apples was selected and examined to determine its taxonomical characteristics. The bacterium was identified as the genus Acetobacter sp_ based on morphological, cultural and biochemical properties. A9 strain produced acetic acid from ethanol and decomposed acetic acid to $CO_2$ and $H_2O$. They produced dihydroxyacetone from glycerol but did not produce y-pyrone from glucose and fructose. When A9 strain was cultivated statically in Hestrin and Schramm liquid medium(HS medium). thick cellulose pellicle was formed_ Higher cellulose production was obtained in the shaken culture using HS medium at 100 rpm.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.274-286
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• 2009

Lignocellulosic biomass is the most abundant raw material for bioconversion in many country. However the high costs for pretreatment and enzymatic hydrolysis currently deter commercialization of lignocellulosic biomass, especially wood biomass which is considered as the most recalcitrant material for enzymatic hydrolysis mainly due to the high lignified structure and the nature of the lignin component. Therefore, overcoming recalcitrance of lignocellulosic biomass for converting carbohydrates into intermediates that can subsequently be converted into biobased fuels and biobased products is the primary technical and economic challenge for bioconversion process. This study was mainly reviewed on the research trend of pretreatment with lignocellulosic biomass in bioethanol production process.