• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.120-127
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• 2011

For the development of the environment-friendly insulating composite materials, natural cellulose (wood chip and sawdust) was used as a core material and activated Hwangtoh was used as a binder. Various specimens were prepared with the water/binder ratio and natural cellulose/binder ratio. The physical properties of these specimens were then investigated through compressive and flexural strength test, absorption test, hot water resistance test, thermal conductivity, measurement of pore distribution and observation of micro-structures using scanning electron microscope (SEM). Results showed that the absorption ratio increased with the increase of natural cellulose/binder ratio but decreased remarkably with the increase of polymer/binder ratio. The compressive and flexural strength development varied appreciably with the increase of water/binder ratio and natural cellulose/binder ratio. On the other hand, thermal conductivity decreased with the increase of natural cellulose/binder ratio and polymer/binder ratio. Through SEM, it was found that activated Hwangtoh that reacted with water formed a hydrate crystal leading to the compact structure and the total pore volume of the specimen using activated Hwangtoh was smaller than that of the non-activated Hwangtoh.

• Bulletin of the Korean Chemical Society
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• v.27 no.4
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• pp.519-523
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• 2006

Poly(dimethyl siloxane) (PDMS) has been employed as a microchip material for DNA separation in microfluidic condition. Different sieving molecules such as cellulose derivatives having glucose building block (methyl cellulose (MC), hydroxyethyl cellulose (HEC), and hydroxypropyl methyl cellulose (HPMC)) and polyethylene oxide (PEO) having linear (ring-opened ethylene oxide) unit were used and their performance was compared in terms of separation efficiency and resolution. In general, PEO showed better separation performance than cellulose derivatives probably due to the nature of linear shape polymer conformation. It was possible to perform at least 15 consecutive running with 1.2% PEO at the electric field strength around 200 V/cm. Fast analysis of the standard $\Phi$X 174 RF DNA/Hae III (less than 130s) was obtained with the number of the theoretical plate around 250,000/m. Our PMDS microchip was applied to the measurement of CAG repeat number, which is related to male infertile disease.

• Textile Coloration and Finishing
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• v.32 no.3
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• pp.142-149
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• 2020

The purpose of this study was to investigate the dyeing properties of mugwort extract by nano-cellulose(n-cell). When dyeing cotton, rayon(artificial silk, called Ingyeon) and silk with mugwort extract, the difference with and without 2 wt% n-cell which it diluted to 0.6% treatment was compared. It was found that the addition of n-cell changed the values of L^∗, -a^∗(+red ~ -green), and b^∗(+yellow ~ -blue) of all scoured cotton, rayon and silk fabrics, compared to dyeing only mugwort extract. Furthermore, it was confirmed that the ΔE and the K/S value slightly increased in all of the dyed cotton, rayon, and silk fabrics treated with n-cell at the same time as dyeing compared to the untreated ones. Therefore, by treating the fabric with n-cell, a natural cellulose component, at the same time as dyeing, it is expected to maintain stable fastness, which is a disadvantage of dyeing using natural dyes, and contribute to the utilization and commercialization of other natural dyes.

• Korean Journal of Microbiology
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• v.45 no.3
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• pp.275-280
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• 2009

The optimal medium compositions for the production of bacterial cellulose (BC) by a Acetobacter sp. V6, which was isolated from the traditionally fermented vinegar in Korea, were investigated in static cultures. The optimum medium compositions for BC production were 3% glucose, 3% soytone, 0.8% $K_2HPO_4$, and 0.4% ethanol, respectively. Adding $NaH_2PO_4$ or $KH_2PO_4$ had not shown the increase in BC production. Under the optimum medium compositions, the highest BC production was 44.67 g/$m^2$ in 8 days and the thickness of BC pellicle was about 1 cm. Structural properties of BC produced in the optimal medium were studied using Fourier-transform infrared spectroscopy and X-ray diffractometer. BC from the optimal medium was found to be of cellulose type I, the same as typical native cellulose. No difference in the compositions between bacterial and plant celluloses, but BC showed unique micro-network structure and high crystallinity (82%).

• The Research Journal of the Costume Culture
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• v.24 no.6
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• pp.777-787
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• 2016

This study was carried out in order to provide useful data for planning fabrics of summer eco-friendly fashion products. The fabrics used in this study were four cellulose fibers: cotton, cotton/mulberry blended, flax, and flax/lyocell blended. Dyeing with natural indigo was carried out under three different reducing conditions (i.e., general, eclectic, and eco-friendly) that have different reducing agent and pH levels, and hydrosulfite and glucose were used as a reducing agent. The dye uptake (K/S value) of fabrics dyed with natural indigo by a reducing condition was the highest at 660nm. Regardless of the fabrics, dye uptake was the highest under the general reducing condition and the lowest under the eco-friendly reducing condition. Under different reducing conditions, the dye uptake of natural indigo fabrics with the maximum absorption wavelength indicated a difference. The colorfastness of cellulose fabrics that were dyed with natural indigo had a rate of 4 to 5 except for rubbing fastness, which indicated good colorfastness. Additionally, natural indigo-dyed cotton and flax fabrics had good antibiosis. When the color characteristics of fabrics dyed with natural indigo were measured, all of the three reducing conditions created purple blue (PB) colors, and the color characteristics of dyed fabrics by reducing condition and fabric showed significant differences.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.81-88
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• 2022

Acetic acid bacteria (AAB) are versatile organisms involved in the production of variety of fermented foods, such as vinegar and kombucha, and products of biotechnological relevance, such as bacterial cellulose. In the present study, Malatya apricot, a variety with protected designation of origin (PDO), and vinegar samples produced using various fruits were used to isolate AAB. The 19 AAB isolates obtained were typed using (GTG)5 fingerprinting, and the ones selected were identified by sequencing either 16S rDNA alone or in combination with 16S-23S rRNA internal transcribed spacer region or ligA gene. While all apricot isolates (n = 10) were Gluconobacter cerinus, vinegar isolates (n = 9) were composed of Komagataeibacter saccharivorans, Acetobacter syzygii, and possible two new species of AAB, Komagataeibacter sp., and Gluconobacter sp. (GTG)5 fingerprinting showed the presence of several genotypes of G. cerinus in the apricot samples. Screening for some technologically relevant properties, including thermotolerance, ethanol tolerance, and cellulose production capability, showed that all Komagataeibacter and some Gluconobacter isolates could tolerate the temperature of 35℃, and that vinegar isolates could tolerate up to 8% ethanol. One isolate, Komagataeibacter sp. GUS3 produced bacterial cellulose (1 g/l) and has the potential to be used for cellulose production.

• Korean journal of food and cookery science
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• v.14 no.4
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• pp.333-338
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• 1998

On the mutagenicity induced by 2-aminofluorene (2-AF) with S9 mix and N-Methyl-N＇-Nitro-N-Nitrosoguanidine (MNNG) without S9 mix, the antimutagenic effects of dietary fiber (total dietary fiber, u-cellulose and pectin) from Yam were examined by the Ames assay using Salmonella typhimurium TA98 and TA100. Total dietary fiber, $\alpha$-cellulose ind pectin from natural and cultural Yam didn＇t have mutagenicity. Most of sample dietary fiber showed the antimutagenicity. Total dietary fiber from cultural Yam was more effective than that from natural Yam on mutagenicity induced by 2-AF and MNNG. $\alpha$-cellulose from cultural Yam was more effective than that from natural Yam on mutagenicity caused by 2-AF and MNNG. Pectin from natural and cultural Yam had antimutagenic effect on mutagenicity induced by MNNG. In this study, antimutagenicity on MNNG was more effective than that on 2-AF. Antimutagenic effect of Samples had influence on incubation time. $\alpha$-cellulose and pectin from natural and cultural Yam showed stronger antimutagenic effect than standard $\alpha$-cellulose and standard pectin, respectively, on mutagenicity induced by 2-AF and MNNG.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.5
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• pp.866-880
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• 2021

This study aimed to ex situ colorize laccase-entrapped bacterial cellulose (BC) with natural phenolic dyes, namely,madder, turmeric, and cochineal, and to determine the effect of laccase entrapment on the dyeability of BC using color strength (K/S) analysis. Results showed that laccase entrapment improved the dyeability of BC and that pre-entrapment was the most effective method, compared with meta-entrapment and post-entrapment methods. In addition, surface characterizations confirmed the successful entrapment of laccase inside the BC nanostructure and retention of the cellulosic and crystalline structures of BC. The washing durability test confirmed that the K/S value of BC had improved after laccase entrapment. Furthermore, laccase-entrapped BC colorized with cochineal dye had the highest washing durability due to the high molecular weight of cochineal dyerelative to the other dyes. This study suggests a novel method for enhancing the dyeability and washing durability of BC colorized ex situ with natural phenolic dyes by laccase entrapment.

• Textile Coloration and Finishing
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• v.21 no.2
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• pp.29-39
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• 2009

The color mixture, obtained from Indigo and Japanese pagoda tree, was applied to cellulose fibers such as cotton, linen and rayon to diversify color gamut of natural dyes. The color mixture was tried with two different methods. The first process was that cellulose fibers were dyed with $5{\sim}25%$ owf Japanese pagoda tree solution, and then dyed 1 to 4 times with Indigo. The second process was dyeing 1 to 7 times with Indigo, followed by dyeing with $5{\sim}25%$ owf Japanese pagoda tree solution. K/S value of the dyed fibers with one colorant and color mixture increased in the order of linen, cotton, rayon. It was also found that the first process could give higher K/S values than the second process.

• Journal of Sericultural and Entomological Science
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• v.19 no.1
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• pp.9-13
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• 1977

This experiment was carried out to know relationship between economical characters and kinds of extracted cellulose powders, extracting methods and cellulose composition. The results obtained are summarized as follows; 1. Among the matters for cellulose resources, mulberry branch is the most useful in economical characters such as larval weight, ratio of cocoon shell and mortality, followed by pine branch. 2. Though both PA-method and NaOH-treatment are equally effective in the larval growth, the latter may be more recommendable because of its economical convenience. 3, It may be desirable to add 15 to 22.5 per cent of cellulose powder per dry matter in the diet composition