• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.410-413
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• 1998

Since early of 1980's, high. performance fiber has been developed by processing of ultrahigh molecular weight polyethylene(UHMWPE). UHMWPE fibers have high strength high modulus and excellent impact properties due to the strong C-C bond. Furthermore, the specific gravity of UHMWPE fibers is less than 1.0g/$\textrm{cm}^2$, which makes it possible to produce composites that combine good mechanical properties with low specific mass. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.200.3-200.3
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• 2003

Reactive oxygen species(ROS) are produced at a high rate continuously as a by-product of aerobic metabolism. Several lines of evidence provided that ROS appears to cause to develop aging and various diseases. High level of hyaluronic acid with decreased molecular weight has been detected in patients with inflammatory diseases including rheumatoid arthritis. Hyaluronidase is an endohexosaminidase that initiates the degradation of hyaluronic acid with high molecular weight. Prunus persica Batsch var. davidiana Maximowicz has been known as a korean folk medicine for treatment of neuritis and rheumatism. (omitted)

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.2
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• pp.171-175
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• 1986

Pectic substance of hot pepper crude cell wall was fractionated during ripening and softening. The pectic substance was divided ionically associated pectin(IAP) and covalently bounded pectin with hemicellulose(CBP). And then, the composition and the modification of the pectic substance using gel filtration chromatography were studied. The polyuronide associated with the CBP increased owing to decreasing of pectin bound hemicellulose linked to galactose by the turning stage showed softening. The molecular weight profiles of IAP shifted from low molecular weight profiles of IAP shifted from low molecular weight to high molecular weight polymers. While, the CBP changed from high molecular weight to low molecular weight polymers during ripening. It is suggested that the changes in the pectic substance associated with fruit softening should involve the alteration of CBP-bound hemicellulose like galactan.

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.878-888
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• 1994

In order to investigate the fracture behavior of ABS terpolymer under the tension and impact load, varing the content of rubber, molecular weight of SAN, content and kinds of lubricant, tension speed, the mechanical properties were measured and SEM pictures of fracture area were taken. Under the tension, the tensile strength increased as rubber content and lubricant content decreased, while molecular weight and tension speed increased. The deformation of area near fracture site did not occur as rubber content, tension speed and molecular weight decreased and liquid lubricant was used. And in the shape of fracture seemed phase seperation. Under the impact load, the notched izod impact strength increased as rubber content, molecular weight, ambient temperature and lubricant content increased. In the SEM picture, the strength was high white the fracture surface was small.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.695-700
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• 2021

The purpose of this study was to prepare low-molecular weight collagen using a commercial proteolytic enzyme (Protamex) from collagen extracted from feet of Korean native chicken and to investigate the quality characteristics of this collagen. The collagen content of Korean native chicken feet was 13.9 g/100 g, which was higher than the 6.21 g/100 g of general broilers. It was found that the content of low molecular weight collagen increased as the concentration of proteolytic enzymes and reaction time increased. In particular, reaction with 1% Protamex for 7 h resulted in 55.6% of low molecular weight (1,000-5,000 Da) collagen content, and the average molecular weight was 5,390 Da. Regarding the texture of the enzyme-treated collagen, the collagen with high molecular weight peptides decomposed into low molecular weight peptides, and the gel type could not be formed, whereas the sol type was maintained.

• Journal of Ginseng Research
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• v.19 no.3
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• pp.244-248
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• 1995

Water-soluble browning pigments were artily purified from Korean red ginseng through the several procedures such as fractionation by n-butanol, precipitation by ethanol, dialysis and gel filtration. At least four kinds of water-soluble browning pigment were separated from each other, two kinds of low-molecular-weight and two kinds of high-molecular-weight pigments.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.761-766
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• 1999

In this paper, high pressure phase behavior in the binary polyethylene/butane and polyethylene/dimethyl ether has been studied. The pressure-temperature diagrams in polyethylene/butane were shown by increasing concentration for molecular weight standards, that is, $M_w=700,\;1000$ and 2000. It is found that the temperature and the pressures go up with increasing in concentrations for each molecular weight, but the latter lower in concentrations over 16 wt % polyethylene. In addition, the phase behaviors for each molecular weights with about 5 wt % polyethylene are shown in pressure-temperature, and pressures increase with increasing in molecular weight($M_w=700,\;1000$, and 2000). The phase behaviors in polyethylene/dimethyl ether are determined according to its molecular weight, and are shown for a range of pressures of 40~280 bar and temperatures of about $120{\sim}220^{\circ}C$. It is shown that in pressure-temperature of polyethylene/dimethyl ether the pressure increases with increasing in polyethylene molecular weight, and the difference in pressure for each molecular weight shows by about 60 bar. The gap in pressure between polyethylene/butane and polyethylene/dimethyl ether system with 5 wt % polyethylene for each molecular weight standards indicates about 25(700), 90(1000), and 100 bar(2000), respectively.

• Polymer(Korea)
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• v.27 no.4
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• pp.307-312
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• 2003

Hollow fiber was prepared from the blend of a high density polyethylene (HDPE)/ultra high molecular weight polyethylene (UHMWPE). The changes in the morphology and mechanical property of the hollow fiber were investigated. The commercial product (Sterapore), having a high water permeability, was analyzed with viscosity measurement and FT-IR. The molecular weight of Sterapore was very high and its surface was coated with a vinyl alcohol/vinyl acetate copolymer. The content of UHMWPE in the HDPE/UHMWPE blend was limited below 10 wt%. In order to improve the dispersion of UHMWPE, a mineral oil should be introduced in the blend. The morphology and mechanical property of the hollow fiber of HDPE/UHMWPE blend were similar to those of the commercial product.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.2
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• pp.242-249
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• 2007

Deposition fluxes of polycyclic aromatic hydrocarbons (PAHs) were measured at the Chonbuk National University located in Jeonju between June and November 2002. Fluxes of gaseous and particulate PAHs were separately obtained using a water surface sampler (WSS) and a dry deposition plate (DDP). Most of PAHs were deposited in the gaseous form since the low molecular weight PAHs dominates in the atmosphere. The deposition velocity of particulate PAHs was higher than that of gaseous PAHs when the molecular weight was low, but substantially decreased as the fine particle fraction increased with molecular weight. The deposition velocity was generally higher at high wind speeds. However, increase in the deposition velocity in unstable atmospheric conditions was also observed for gaseous PAHs of intermediate molecular weight.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.608-611
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• 2000

To separate chitosanoligosaccharides easily by size exclusion, an coencapsulating technology of substrate and enzyme was developed. Chitosan and chitosanase were enveloped in this membrane and the product released to medium by size exclusion. The lower limit of the alginate concentration and the agitation speed were 0.5% and 40 rpm, respectively. Membrane thickness and capsules diameter were $10{\mu}m$ and approx. 3.0mm, 1.5mm, respectively. The molecular weight difference by concentration and cps of alginate were of little significance. And also, the molecular weight of distribution according to enzyme concentration was low concentration of enzyme produced high molecular weight of oligosaccharides. At 1.5mm size of capsule, product diffusion rate to outer part was higher than other capsules. The molecular weight distribution of the released oligosaccharides ranged from 1000 to 6000 Da.