• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.303-303
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• 2006

In-situ ring opening polymerization of ${\varepsilon}-caprolactum$ was carried out in the presence of aminoethylaminopropylisobutyl POSS and stoichiometric amount of adipic acid. The covalent bond formation of POSS on the polyamide was confirmed by the appearance of FT-IR peak at $1123\;cm^{-1}$ that corresponds to the Si-O stretching of POSS structures. Gradual decrease in melting endotherm peak was observed on loading POSS in PA6/POSS nanocomposites. Sharp increase in intrinsic viscosity was observed upto 2.5 wt % loading POSS in the polyamide 6 nanocomposites. These nanocomposites were further characterized using nuclear magnetic resonance, melt viscosity and X-ray diffraction.

• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.1
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• pp.1-19
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• 2012

According as gradually increasing the demand for eco-friendly at the printing process, it has been progressed fairly development. Especially, the inks are used by soy oil beginning of ink industry for preventing environment, it is possible to make eco-friendly inks with vegetable ester. So it is not necessary to use petroleum-based solvents at all for preventing environment. These eco-friendly inks have a benefits they are able to use the renewable resource. But basically vegetable oils have that reduce the VOC(Volatile Organic Compound) and high viscosity, high solubility properties. So if the vegetable oils use in the ink, set off problem occur on the paper because of slow drying time. In case of vegetable ester, it has similar the molecular weight and kinetic viscosity with hydrocarbon solvent, it is able to control the power of dilution about the resin. So, it has benefit that solve the problem of the existing eco-friendly inks. In this study, different types of ester were made by six types of vegetable oils and used ester in the varnishes and inks properties are comparison with hydrocarbon solvent based ink. By considering the intrinsic properties of vegetable oil, ester used to analyze the changes in ink properties, using ester varnish is applied to study the rheology characteristics and emulsification with inks.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.29-36
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• 2000

The shape of the polymers in the mixed alkoxide solutions of Si(OC2H5)4 and Zr(n-OC3H7)4 with various water contents (1, 2, 4, and 8 in molar ratio to alkoxide, r) and catalysts was examined by rheological measurements, and its relation with fiber drawing behavior of the solutions was described. It was found that fibers could be drawn in the viscosity range 1~100 P from the acid-catalyzed solutions with lower water contents of the molar ratio H2O/alkoxide, $r{\leq}2$. On the other hand, no fiber could be drawn from the acid-catalyzed solutions including a large amount of water($r{\geq}4$) and the base-catalyzed solutions. The relation between the intrinsic viscosity [${\eta}$] and number average molecular weight ${\bar{M}}n$, namely $[{\eta}]=K{\bar{M}}n{\alpha}$, has shown that the acid-catalyzed spinnable solution (r = 1 and 2) had linear polymers where the exponent a's were about 0.56 and 0.81, whereas non-spinnable solutions (r = 4 and 8) had three dimensional network polymers or spherical particles where the exponent a's were 0.41-0.51 and 0.35.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.900-903
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• 2009

An oat gum was extracted from whole seeds of a drought harvested oat (Avena sativa). Oat gum presented a ${\beta}-glucan$ content of 65%(w/w) and an intrinsic viscosity of 141 mL/g. Gelling capability of oat gum at different concentrations was investigated. Gel hardness increased from 0.08 to 0.25 N as the oat gum concentration changed from 5 to 10%(w/v). Whippability, foam stability, emulsion stability, and reduced viscosity of oat gum at different pH were also investigated. Oat gum whippability was maximum at pH 7 (146%), while the higher foam and emulsion stability values were found at pH 9 (88 and 96%, respectively). The gum reduced viscosity increased from 715 to 958 mL/g as the pH changed from 7 to 9. Oat gum shows great potential as a gel forming, thickening, and stabilizing agent.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.453-459
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• 1989

A strictly aerobic bacterium forming yeller pigment and a highly viscous polysaccharide was isolated. The bacterium was identified as Pseudomonas mendocia. The polysaccharide was presumed to be ${\beta}-glucan$ with o-acetyl group in its structure and the constituent sugar components were glucose and rhamnose in the molar ratio of 2.1: 1.0. The intrinsic viscosity was 64.73dl/g. The apparent viscosity of 1% aqueous solution was 428 mPa.s. at $42\;sec^{-1}$ and the yield stress of the solution was 8.89Pa. The polysaccharide did not have thermal stability but show pH and salt stability.

• Applied Biological Chemistry
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• v.34 no.1
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• pp.75-76
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• 1991

Bran structure and gelatinization property of upland and lowland japonica waxy brown rice were compared. Dimension, weight and number of aleurone layer were similar between upland(Nonglimna 1) and lowland(Shinsunchalbyeo) rices, but the aleurone layer and pericarp of upland rice were thicker. Water uptake rate of upland rice at $60^{\circ}C$ was lower than that of lowland one. There was no difference in intrinsic viscosity between two rice starches. Upland rice starch had lower onset temperature, narrower gelatinization temperature and lower water content lot gelatinization compared with lowland rice starch.

• Publications of The Korean Astronomical Society
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• v.8 no.1
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• pp.163-168
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• 1993

At intermediate mass transfer rates, accretion disks in binary star systems undergo a thermally-driven limit cycle instability. This instability leads to outburst episodes when the disk is bright and the flow through the disk is rapid separated by long intervals when the disk is dim and the flow through it is low. This intrinsic outburst mechanism can help to understand a wide range of astrophysical phenomena from dwarf novae to soft X -ray transients involving white dwarf, neutron star, and black holes. and to a deeper understanding of the mechanism of angular transport and viscosity in the accretion disk.

• Polymer(Korea)
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• v.34 no.5
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• pp.415-423
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• 2010

Poly(vinyl alcohol)(PVA) with high degree of hydrolysis of above 98% was dissolved in dimethyl sulfoxide(DMSO), and the shear viscosity was measured up to $C{\simeq}0.14\;g/mL$ in the semi-dilute solution regime. Next, as probe particle, polystyrene(PS) latex was introduced into this matrix system and its delayed diffusion due to polymer concentration was investigated by means of dynamic light scattering. When the solution viscosity of PVA/DMSO was plotted against the reduced concentration $C[{\eta}]$, which is scaled by the intrinsic viscosity, the molecular weight dependence was strongly appeared at C$[{\eta}]$ >2. Some heterogeneties in polymer solution were considered as its source. Contrary, the diffusion of probe particle in the matrix solution was observed as a single mode motion at whole concentration range but its ratio of its diffusion coefficient at solution to that at solvent, D/Do did not show any molecular weight dependence at all. However, the application limit of the stretched exponential function was disclosed at C$[{\eta}]$ >2.5.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.293-298
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• 2015

This study aimed at characterizing the rheological properties and molecular weight of tara gum fractionated with ammonium sulfate. Tara gum was separated into six fractions (F1-F6) at different concentrations of ammonium sulfate, ranging from 12.21 to 28.67% (w/w). The yield of the tara gum fractions ranged between 4.98 and 17.47%, and their intrinsic viscosity ranged from 9.38 to 12.44 dL/g. The highest values of Huggins coefficient (k') and viscosity-molecular mass were observed in fraction F3. The shear viscosity of the tara gum fractions was measured by a cone-plate viscometer, clearly showing shear thinning behavior. Size-exclusion chromatography results showed that the molecular weight ranged between 635.42 and 776.71 kg/mol, and the F3 fraction exhibited higher values of molecular weight.

• Journal of the Korean Society of Clothing and Textiles
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• v.14 no.4 s.36
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• pp.262-273
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• 1990

The purpose of this study is to investigate the softening effect of cellulase-treated cotton fabric and the damage on the fabric which is accompanied by the treatemnt. Cotton fabric is treated with cellulase under various concentrations and time, and the weight loss, hand values (by KES), surface characteristics, moisture regain, tensile strength, copper number and intrinsic viscosity of the treated samples and untreated samples have been compared. The results are as follows: 1. The weight loss of cotton fabric increased as the concentration of cellulase and the treating time increased. 2. The enzyme treatment had little effect on the stiffness of the treated samples but anti- drape stiffness decreased for the treated samples. Fullness and softness of the treated samples increased and crispness decreased with the lowest level reaching after two hours of the treatment for all concentrations. Scrooping feeling of the treated samples increased and flexibility with soft feeling increased as the treating time and the concentration of cellulase increased. 3. Moisture regain of the samples decreased as the treating time and the concentration of the enzyme increased and the treated fabric showed cracks on the fiber surface, and much surface fibers on the fabric have been removed after the treatment. 4. Tensile strength of the samples decreased as the treating time and as the concentration of cellulase increased, and the copper number increased while the intrinsic viscosity decreased as the treating time increased, but cellulase concentration had a little effect.