• Archives of Pharmacal Research
• /
• v.9 no.4
• /
• pp.193-199
• /
• 1986

The release of heparin from monolithic devices composed of different ratios of polythylene oxide (PEO MW 20,000) and hydrophobic polydimethylsiloxane or polyurethane was investigated. Water soluble PEO blended into the polymers provided a controlled release of heparin. The release rate of heparin could be controlled by varying the content of PEO. The heparin release rate from the devices increased as the content of PEO in the devices increased. The release mechanism may be associated with the creation of pore of domain through the devices following the swelling and the change in the physical structure of the polymer network. Hydrophobic polydimethylsiloxanes and polyurethanes containing PEO can provide an antith rombogenic material for prologed release of heparin from blended system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.905-906
• /
• 2012

In this paper, we develope new goods for helping of increasing income that tube arched POP by using PVC papers to PET plating films. General market is supported with high quality POP by using specified goods and increased value of goods. Also, it is easily developed with new material with re-combination of existing materials. The purpose of this paper is that good design and materials of POP spreads widely not only big markets but also small shops.

• Electrical & Electronic Materials
• /
• v.4 no.1
• /
• pp.45-52
• /
• 1991

본 논문은 기중 코로나 방전에 의하여 생성된 캐리어를 Teflon-FEP 표면에 균일하게 공급하였을 때 Teflon-FEP를 통하여 흐르는 코로나 대전전류 특성에 대하여 연구하였다. 불소를 함유한 Teflon-FEP는 코로나 대전전류에 극성효과가 현저히 나타난다. 즉 정극성 캐리어는 벌크내를 쉽게 이동하나 부극성 캐리어는 안정하게 trap되어 벌크내를 이동하기 어렵기 때문에 부극성 코로나 대전전류 보다 정극성 코로나 대전전류가 크게 흐름을 알았다. 이와같이 극성효과가 나타나는 것은 Teflon-FEP가 전자 친화력이 있는 불소를 함유하고 있기 때문임을 제시하였다. 이러한 사실은 Polysulfone(PSF), High density Polyethylene(HDPE) 및 Polythylene Terephtarate(PET)의 코로나 대전전류 특성으로부터 확인할 수 있었다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1991.10a
• /
• pp.64-68
• /
• 1991

It happened that there was a sudden peak with the capacity of change, when I measured the capacity of change, cubical expansion and Thermally Stimulated Current on the Cross - Linked Polythylene. Crystal melting began at 375 K and changed into formaless shapeless at 380 K. The conduct of a particle on the surfase of dipole, electron trap was founded to be ion conduction nature under the low electronic field, wherase, the electron nature under the high electronic field. Consequentity, under the semi-conduction layer electronic a particle was injected to inter-fase and accumulated for a time and appeared to be TSC.

• 전기의세계
• /
• v.29 no.11
• /
• pp.727-732
• /
• 1980

The main purpose of this paper is to study on the effect of contact state between metal-polymer interface in electrical conduction of polymeric materials under low field region. The electric conduction of polythylene (PE) sandwitched in between two gold (Au) electrodes was lower than that of PE Sandwitched in between two Aluminium (Al) electrodes under low external field. The discharge current of PE which have been treated by the high field application is also obtained some results under no external field. The obtained results can suggest that the material of electrode come to influence on the electrical conduction of polymeric materials and are important as a basis for analysing the data on TSC. It is also suggestive that results of observation must be considered in cases of insulation design of electrical machinery.

• The Korean Journal of Ceramics
• /
• v.5 no.3
• /
• pp.265-269
• /
• 1999

Polyethylene was modified with silanol groups on its surface by photografting of vinyltrimethoxysilane in vapor phase by using benzophenon as a polymerization initiator and by hydrolyzing the methoxysilane groups into the silanol groups with HCI solution. The modified polyethylene formed a dense and homogeneous apatite layer on its surface in a solution with ion concentrations 1.5 times those of human blood plasma within 21 days. This kind of biomimetic process could provide techniques for fabricating apatite-polymer composites with three dimensional structure analogous to the natural bone.

• Journal of Ginseng Research
• /
• v.15 no.1
• /
• pp.21-30
• /
• 1991

This study was conducted to know the elects of light intensity of polyethylene net shading on the growth status, photosynthesis and root yield of ginseng plants. Polyethylene net shading of loft transmittance was the best one among light intensities of polyethylene net used in view of photosynthesis and decreasing of early leaf defoliation. According to increase of light intensity under the shading chlorophyll contents of ginseng leaves were decreased. As it was increased over 2 mg/g Photosynthesis and total saponin of leaves showed on the decrease remarkably. The rate of alternaria blight of ginseng plants showed the positive correlation between light intensity and leaking rate. The shading of 10% transmittance in root yield was increased by 40% in 6-year-old ginseng plant as compared with common straw shading, due to decreased missing plant and increased root weight.

• Journal of Ginseng Research
• /
• v.6 no.1
• /
• pp.30-37
• /
• 1982

This study was conducted to investigate the water vapor permeability of packaging film, Al- foil laminated paper, and sorption properties of dehydrated and powdered foods. The results are as fellows. 1. Absorption rate of each products was greately affeoted by physicochemical properties of foods rather than initial moisture contents of the products. 2. The absorption rate of each products were in the order of freeze dried coffee, spray dried coffee, freeze drie4 ginseng extract, spray dried ginseng extract, ginger tea, black tea, citrus juice Powder and ssang wha tea. 3. Most of the products such as freeze dried coffee, spray dried coffee, freeze dried ginseng extract, ginger tea and black tea have shorter than a month of shelf life. 4. The stability of the products were greatly affected by its desorption properties than the degree of desorption of moisture. 5. Water vapor permeability of packaging materials which are laminated Al-foil with polythylene and glassin paper were mainly affected of thickness of Al-foil and polyethylene.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.1
• /
• pp.52-59
• /
• 2000

In order to develop the transparent anti-static film with higher than 80% transparency to visible light, organic conductive compounds, N-methyl phenazinium 7,7,8,8-tetracyanoquinonedimethane (TCNQ) com-plex salts was synthesized and bar-coated on the polythylene terephthalate (PET) film using polymer binders. The best surface properties were obtained when acrylic binder was used. A single layer of TCNQ made of a acrylic binder showed a surface resistance of 10\ulcorner $\Omega$/ , a conductivity of 10\ulcorner S/cm, and a transparency of 75%. An optical microscopic examination revealed that the binder was first solidi-fied on the surface of PET film over which the needle-shaped TCNQ crystals were grown. An acrylic polyol coating over the TCNQ layer improved the transparency to 87%, becuase the acrylic polyol covers the surface of TCNQ crystals to reduce the surface roughness. This conductive material has thermal stability at room temperature and 4$0^{\circ}C$ over 4,000 h.

• Microbiology and Biotechnology Letters
• /
• v.20 no.2
• /
• pp.190-195
• /
• 1992

In the polyethylene glycol/dextran aqueous two-phase systems, volume ratio was increased and partition coefficient was decreased with the increase of potyethylene glycol molecular weight and concentration. However the volume ratio was decreased and the partition coefficient was increased with the increase of dextran molecular weight. On the other hand, the volume ratio and the partition coefficient were decreased with the increase of dextran concentration. Continuous enzymatic hydrolysis of soluble starch with $\alpha$-amylase which was produced by Bacillus amyloliquefaciens IF0 14141 was investigated in polyethylene glycol/dextran aqueous two-phase systems. Nonreacted soluble starch and $\alpha$-amylase were reused in these systems. $\alpha$-Amylase activity was maintained more than 100 hrs by recycling of $\alpha$-amylase from bottom of settler to reactor.