• Transactions on Electrical and Electronic Materials
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• v.18 no.6
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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.

• 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.

• Journal of the Korean Society of Safety
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• v.10 no.3
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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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• v.5 no.1
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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.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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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.

• Korean Journal of Microbiology
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• v.4 no.2
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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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• v.6 no.3
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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.

• Journal of the Korean Chemical Society
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• v.4 no.1
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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.

• Microbiology and Biotechnology Letters
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• v.5 no.1
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• pp.18-23
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• 1977

Experiments were carried out to pursue the availability and the feasibility of utilizable cellulosic materials as substrate for the production of cellulosic single cell protein. The resuluts were obtained as fellows. 1. Effects of carbolydrates as a sole carton source on the growth of Cellulomonas flavigena KIST 321 were examined. The result showed that cellulose and xylose would be most utlizable for cell mass production. 2. Alkaline treated waste papers and clothes resulted in good growth of the organism than intact ones did. However the waste papers as substrate of cellulosic fermentation were not digestible, even if the meterial was treated with alkalies. 3. Rice straw, rape straw and panic grass appeared to be good substrates for the cell mass production. 4. Leaves were proved to be a good substrate for the cell mass production, but wood sawdust was hardly digested by merely alkaline treatment. 5. When cellulosic wastes as the substrate were examined into the concentration of alkaline solution, the result suggested that the best productivity of cell mass from cellulosic materials was obtained on treatment with 0.8∼1.0％ NaOH solution. 6. The productivity of cell mass was increased by washing out with water after alkaline treatment of newspaper, pine sawdust, lime sawdust and pine leaf.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.629-632
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• 2001

The strain FJ1 isolated from a rotten wood showed high activity to hydrolysis of cellulosic materials. The strain produced largely enzymes related in hydrolysis of cellulose and hemicellulose, such as CMCase, xylanase, ${\beta}-glucosidase$ , and avicelase. The culture conditions(pH, temperature, inoculation concentration) and substrate specificity to various cellulosic materials were examined to elevate productivity of the enzymes. The enzyme activities of CMCase and xylanase were 13.5U/ml and 24.3U/ml in agitation culture using Mandel's medium, respectively. The high activity of the enzymes was earned when mixed cellulosic materials of rice straw, sawdust, and pulp as substrates, indicating that the strain FJ1 could use crystalline substrates.