• Transactions on Electrical and Electronic Materials
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• 제18권6호
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• pp.338-340
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• 2017

Breakdown of solid insulating materials in power equipment could result in undesired outages and replacements, and may be due to an increase in electric stress on the material. Therefore, it is necessary to conduct a proper diagnosis of materials before their practical use. In this work, a few inherent properties of different non-cellulosic insulating materials, such as Nomex, Teflon, laminated Nomex, glass bonded mica, epoxy resin bonded mica paper, and epoxy resin bonded fiberglass, have been evaluated by performing non-destructive dielectric diagnostic measurements, and an attempt has been made to correlate these basic parameters to evaluate the breakdown strength (BDS). An equation has been proposed using a basic theory which defines the correlation between the BDS, dielectric constant, dissipation factor, sample thickness, and volume resistivity. The results obtained from the equation are also compared with the experimental values. The suggested equation will be helpful to predict the BDS of any non-cellulosic material without experimentation in the laboratory.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.331-336
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• 1991

섬유성 물질을 발효기질로서 사용하기 위하여, 분리균 Pseudomonas sp. LBC-505의 cellulase를 이용하여 여러 종류의 천연 섬유성 물질에 대한 당화실험을 행하였다. Cellulase 복합체의 생산은 glucose에 의하여 저해되었고 CMC, avicel, 밀기울, 볏짚 등의 섬유성 물질에 의해 유도되었으며, 55(w/v) 밀기울 배지에서 최대 효소활성을 나타내었다. CMCase 와 xylanase의 최적 효소 반응온도는$50^{\circ}C$였으며, $\beta$-glucosidase는 $55^{\circ}C$ 였다. 또한, 이들 효소의 최적 반응 pH 는 모두 6.6이었다. 조효소 단독처리에 의한 천연섬유소의 당화율은 낮게 나타났으나, 5%(v/v) HCl로 실온에서 24시간 전처리한 후 효소반응을 행한 결과 가수분해율이 18.4%(w/w)로 볏집이 가장 양호하였으며, 구성당은 주로 glucose, xylose 및 cellobiose 였다.

• 한국안전학회지
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• 제10권3호
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• pp.62-67
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• 1995

The combustion characteristics of cellulose Insulation treated with several metal complexes such as Aluminium hydroxide, Cupric sulfate pentahydrate, Magnesium sulfate heptahydrate, Manganese chloride tetrahydrate and Tnisodium phosphate dodecahydrate are studied to evaluate the effectiveness as a potential flame retardant for cellulosic materials. In this study, we found that LOI values of cellulosic materials treated with the metal complexes are generally increased with the increase of their content. At high concentration, CS(24% ) and SP(24% ) show high LOI values, suggesting resistance to flame spread, The materials examined in this study were found to be relatively more resistance to smouldering and flaming combustion in comparision with untreated cellulosic material. The flammability behavior of the materials exhibits combustion process as follows : LOI$\rightarrow$smouldering region$\rightarrow$smouldering-flaming spread region$\rightarrow$flame spread region.

• Fibers and Polymers
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• 제5권1호
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• pp.44-51
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• 2004

Three bi-functional reactive dyes such as Bis(vinylsulphone) type, Bis(monochlorotriazine) type and Bis(mononicotinotriazine) type were applied to regular viscose rayon and new regenerated cellulosic fiber ($enVix^ⓡ$) which was prepared from cellulose acetate fiber by the hydrolysis of acetyl groups, and their dyeing properties and fastness properties were compared. enVix exhibited better dyeability and fastness than regular viscose rayon and these results were also explained by the differences in the supramolecular structure of these two fibers.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.13-14
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• 2003

Cellulosic graft copolymers were synthesized to use them as the functional materials. Three methods containing atom transfer radical polymerization (ATRP), macro-azo-initiator (MAI) method, and the polymerization catalyzed by tetrabutylammonium fluoride (TBAF) were performed in this work.

• 미생물학회지
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• 제4권2호
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• pp.11-14
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• 1966

The deterioration of cellulosic materials due to the growth of mildew causes enormous loss to us. It is, therefore, necessary to give adequate protectional treatment against mildew spoilage on cellulosic materials. In this study, fourteen chemicals were treated to the strain of Chaetomium globosum A.T.C.C., then phenyl mercuric acetate (P.M.A) was proved to be a most effective fungicide out of various chemicals. Another chemicals, such as Na-pentachlorophenolate, tuget, $\alpha$-naphthol, caprylic acid and orthocidc were also proved to be effective mildew-proofing agents.

• Fibers and Polymers
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• 제6권3호
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• pp.244-249
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• 2005

enVix is a novel regenerated cellulosic fiber, which is prepared from cellulose diacetate fiber using environmentally friendly manufacturing process. Vat dyeing properties of the enVix were investigated and compared with those ofregular viscose rayon. The enVix exhibited better dyeability than viscose rayon. The colour yields of vat dyes on the enVix were found to be dependent on dyeing temperature as well as the amount of levelling agent and salt. Good build-up and good to excellent fastness properties were obtained on the en Vix fabric.

• 대한화학회지
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• 제4권1호
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• pp.38-43
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• 1957

Purified cellulosic materials suitable for the production of cellulose esters can be prepared from waste cotton (carding waste from textile mill). The most desirable conditions in purifying waste cotton were obtained. Waxy materials were removed by boiling in 2-3% soda ash solution for more than 30 minutes in open vessel at atmospheric pressure. As for bleaching, it is desirable to use the bleaching powder solution containing 1%, available chlorine for 60 minutes at 35 deg. C. Purified cellulosic material was acetylated to fibrous cellulose triacetate, which was fractionated in the solution of 70% monochloroacetic acid using water as a precipitant, and the degree of polymerizaion and molecular weight of each fraction were measured viscometrically, thereon, molecular weight distribution curve was drawn. Analyzing the shape of this curve, most of the polymers were concentrated on the part of higher degree of polymerization. Purified waste cotton was also analysed, the result was that this cellulosic material can be used as a raw material for cellulose esters and ethers.

• 한국미생물·생명공학회지
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• 제5권1호
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• pp.18-23
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• 1977

섬유소자화세균 Cellulomonas flavigena KIST 321로 섬유소 단세포 단백을 생산하기 위하여 우리주변에서 제기되고 있는 각종 섬유소폐기물을 수집하여 기질로서의 사용 가능성을 검토하였는 바 그 결과를 요약하면 다음과 같다. 1. 당유를 유일한 탄소원으로 하였을 때 cellulose와 rylose에서 균체량이 가장 많았다. 2. 폐지유와 폐의유를 기질로 하였을 때 알카리 전처리를 함으로써 알카리 전처리하지 않았을 때보다 균체량이 많았으며, 폐신문지와 같은 인쇄물에서는 균체량이 적었다. 3. 짚류(straws)를 기질로 하였을 때는 대체로 균체수율이 높았으며, 볏짚, 채종대, 피를 기질로 하였을 때 균체량이 많았다. 4. 목재유의 톱밥에서는 균체량이 적었으나 잎류(leaves)에서는 비교적 많았다. 5. 기질의 종류에 따라 전처리시 NaOH농도를 다르게 하여 균체생산량을 조사하였다. NaOH 농도는 기질의 종류에 따라 최적농도가 달랐으나 짚류(Straws)에서는 0.8∼1.0％ 일때가 좋았고, 잎류(leaves)에서는 0.4∼0.6％일때가 좋았다. 6. 각종기질을 알카리 처리후 세척하여 기질로 사용하였을 때 볏짚에서는 균체량이 감소하였으나 소나무 톱밥, 피나무 톱밥, 소나무잎, 폐신문지에서는 증가하였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.629-632
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• 2001

자연계로부터 분리된 FJ1의 환경변수 및 기질 특이성을 본 연구에서 살펴보았는데, 분리 균주 FJ1의 특성은 최적pH, 최적온도는 각각 $6{\sim}7$, $25{\sim}30^{\circ}C$이었다. 또한, 분리균주는 FJ는 Avicel, 섬유소페기물과 같은 결정성 섬유소물질의 분해에 유리함을 알 수 있었다. 본 연구에서는 cellulose의 분해에 관련된 효소를 분비하는 분리균주 FJ1의 환경변수 및 기질 특이성을 조사하였고, 이를 기본으로 하여 배양인자의 조절을 통한 최적의 효소생산 및 생산되어진 효소에 의한 섬유소 페기물(볏짚, 폐지, 음식물 쓰레기 등)의 당화 특성을 검토하고 있다.