• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.602-608
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• 2006

Carbon fiber (CF) reinforced papers using polyacrylonitrile (PAN) based CF and wood pulp were prepared by varying the lengths and the concentrations of CF, and the basis weight of paper to investigate adhesive state between CF and pulp, and physical properties and electrical conductivity of the paper. The reinforcement was caused by physical entanglement and adhesion at the interface of the different fibers rather than by chemical bonds. The tear strength and the thickness of the paper increased as increasing the concentration of CF, while the tensile and the burst strength of the paper decreased. The improved dispersion of CF in the paper was obtained from mixing shorter CF, but the maximum electrical conductivity of the paper was gained from mixing 10 mm chopped CF. The electrical conductivity of the paper increased sharply from 2 wt％ to 8 wt％ of CF showing S-curve, and increased linearly as increasing the basis weight of the paper. Therefore, in order to improve the electrical conductivity and the physical property of the paper, the increase of basis weight of the paper is also important as the increase of CF content in the paper.

• Journal of Arbitration Studies
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• v.17 no.1
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• pp.57-75
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• 2007

Ever since franchising emerged in the industry of distribution, it has been growing explosively in the U.S.A. and all other countries as well. It is a method of expanding a business by licensing independent businessman to sell the franchiser's products and/or services or to follow a format and trade style created by the franchiser using the franchiser's trade marks and trade names. Franchising is a form of business that touches upon many different areas of law including, but not limited to, general contract law, general principles of commercial law, law of intellectual property, competition law, fair trade practices law and other industry specific laws e.g., the Fair Practices in Franchising Act in Korea. Arbitration is a long established, legally recognized procedure for submitting disputes to an outside person(s), mutually selected by the parties, for a final and binding decision. Despite its merits as an alternative dispute resolution, it has been criticized, on the other hand, particularly by franchisees' attorneys on the ground that even though it is required to protect the franchisees against the enforcement of pre-dispute arbitration agreements because of the franchisees' paucity of bargaining power vis-a-vis the franchiser, arbitration cannot afford it. Until recently, however, little has been written about the legal issues pertaining to franchise agreement and arbitration clause contained therein in Korea. This treatise reviews the cases and arguments in relation to the subject especially of the U.S.A., which have been accumulated for decades. The issues addressed herein are the pre-emption by the FAA, the disputes to be arbitrated, the selection and qualification of arbitrators, the place of arbitration hearings and the evidentiary rules applicable, the expenses of arbitration, theory of fiduciary duty and the like, all of which are relevant to franchise agreement.

• Particle and aerosol research
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• v.12 no.2
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• pp.43-50
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• 2016

The influence of basalt fibres on the compressive strength of the geopolymer type binders has been studied. For the experiments 2 types of the basalt fibres were used, namely chopped and spooled fibres. Both types of basalt fibres were 7-10 micron thick in diameter and cut into pieces of 6 mm length. The fibres were mixed with 1% weight to the fly ash powder, followed by the addition of the activator solution (8M NaOH). The pastes obtained were cured at $70^{\circ}C$ for 20 h revealing compact bodies. Compressive strength was measured after 7 days and microstructure observation performed with SEM. The cube bodies ($2{\times}2{\times}2cm$) reveal compressive strength of 47.25(4.03) MPa, while it decreased to 34.0(9.05) MPa in spooled basalt fibres and to 17.33(5.86) MPa in the chopped basalt fibres containing binder, i.e 76% and 36% of the strength without fibres, respectively. The much weaker compressive strength of the chopped fibres containing binder is related to the absence of significant adhesion between the geopolymer binder and the basalt fibres, forming voids instead. Alkali leaching effect of basalt fibres could probably explain the drop in the compressive strength with spooled and chopped fibres, respectively.

• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.814-822
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• 1993

To improve the solubility and adhesion strength of diamine-quinone polymers, urethane group was introduced into the polymer backbone. Urethane group containing polymeric diamines(UDA) were prepared firstly by the decarboxylation of the NCO group in NCO terminated prepolymer obtained from the reaction of MDI and 1.6-hexandiol. The reaction mole ratio of NCO/OH was changed from 1.2 to 2.1 to increase the molecular weight of diamine. From the addition reaction of UDA and p-benzoquinone in THF or DMSO solvent, five kinds of urethane group containing diamine/quinone polymers(PUAQ) were prepared according to the diamine used. IR, NMR, UV-visible spectroscopy and GPC were used to characterize the molecular structure and molecular weight of UDAs and PUAQs. Thermal analysis of polymer by DSC and TGA were carried out according to the molecular weight differency. Also solubility test of UDA and PUAQ with 10 different solvents were carried out to predict the coacting property of the polymers.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.1
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• pp.53-58
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• 2000

In this paper, the variable mechanical strength and dielectric breakdown strength of epoxy composites were measured at boiling absorption condition in order to observe the influences of moisture in out door use. Also, in order to improve water resistance of matrix resin, IPN(interpenetrating polymer network) method which had been already reported, was introduced and the influence was investigated. As Adding filter(SiO2) classified by o[phr], 50[phr] and 100[phr] to two kinds of matrix resin, six kinds of specimens were manufactured. As a result, it was confirmed that the moisture absorption rate was increased and mechanical strength and dielectric breakdown strength were degraded with boiling time and filler content increasing. On the other hand, it was confirmed that moisture absorption rates were decreased and the degrading rates of mechanical strength and dielectric breakdown strength were lowered according to improvement of adhesion strength in case of IPN specimens.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1857-1863
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• 2010

We present the fabrication and characterization of transparent carbon nanotube film (CNF) piezoresistors. CNFs were fabricated by vacuum filtration methods with 65?92% transmittance and patterned on Au-deposited silicon wafer by photolithography and dry etching. The patterned CNFs were transferred onto poly-dimethysiloxane (PDMS) using the weak adhesion property between the silicon wafer and the Au layer. The transferred CNFs were confirmed to be piezoresistors using the equation of concentrated-force-derived resistance change. The gauge factor of the CNFs was measured to range from 10 to 20 as the resistance of the CNFs increased with applied pressure. In polymer microelectromechanical systems, CNF piezoresistors are the promising materials because of their high sensitivity and low-temperature process.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.1.1-1.1
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• 2011

Printed electronics based on the direct writing of solution processable functional materials have been of paramount interest and importance. In this talk, the synthesis of printable inorganic functional materials (conductors and semiconductors) for thin-film transistors (TFTs) and photovoltaic devices, device fabrication based on a printing technique, and specific characteristics of devices are presented. For printable conductor materials, Ag ink is designed to achieve the long-term dispersion stability and good adhesion property on a glass substrate, and Cu ink is sophisticatedly formulated to endow the oxidation stability in air and even aqueous solvent system. The both inks were successfully printed onto either polymer or glass substrate, exhibiting the superior conductivity comparable to that of bulk one. In addition, the organic thin-film transistor based on the printed metal source/drain electrode exhibits the electrical performance comparable to that of a transistor based on a vacuum deposited Au electrode. For printable amorphous oxide semiconductors (AOSs), I introduce the noble ways to resolve the critical problems, a high processing temperature above $400^{\circ}C$ and low mobility of AOSs annealed at a low temperature below $400^{\circ}C$. The dependency of TFT performances on the chemical structure of AOSs is compared and contrasted to clarify which factor should be considered to realize the low temperature annealed, high performance AOSs. For photovoltaic application, CI(G)S nanoparticle ink for solution processable high performance solar cells is presented. By overcoming the critical drawbacks of conventional solution processed CI(G)S absorber layers, the device quality dense CI(G)S layer is obtained, affording 7.3% efficiency CI(G)S photovoltaic device.

• Polymer(Korea)
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• v.25 no.3
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• pp.318-326
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• 2001

PLLA scaffold loaded with gentamicin sulfate (GS) was prepared by emulsion freeze-drying method for the prevention of infection and the improvement of wettability. i.e., the cell- and tissue-compatibility. GS-loaded PLLA scaffolds were characterized by scanning electron microscopy (SEM), mercury porosimetry and blue dye intrusion, and the GS release pattern was analyzed by high performance liquid chromatography (HPLC). GS-loaded PLLA scaffolds with porosity above 50%, medium pore size ranging from 30 to 57 ${\mu}{\textrm}{m}$ (with larger pore diameters greater than 150 ${\mu}{\textrm}{m}$), and specific pore area in the range of 35 to 75($m^2$ /g )were manufactured by varying processing parameter as GS concentration. It was observed that GS-loaded PLLA scaffolds were highly porous with good interconnections between pores for allowing cell adhesion and growth. These scaffolds may be applicable for scaffold as structures that facilitate either tissue regeneration or repair during reconstructive operations.

• Polymer(Korea)
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• v.31 no.6
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• pp.485-490
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• 2007

Hard coating was made on a polycarbonate plate using a sol-gel process with a melamine derivative and silicates, and examined as potential substitutes for automobile glass. Methylated poly(melamine-co-formaldehyde), tetraethoxysilane, and phenyltriethoxysilane were used to form a coating solution. The coatings on the polycarbonate plate were deposited using a sol-gel process. Poly(methyl methacrylate) was coated on the surface of polycarbonate in order to improve adhesion property. The optimum conditions and formulation to obtain excellent physical properties of the coating were determined. Adding the melamine derivative to the coating solution, the pencil hardness of the coating was improved. The hardness of a 3H class pencil, excellent abrasion resistance, and surface uniformity were found in the coated polycarbonate surface.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.233-239
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• 2013

This study is interested in manufacturing the self-cleaning silicate concrete surface impregnant including tetra ethyl ortho silicate, lithium silicate for the repair of the exposed concrete surface and the color concrete requiring the advanced function in view of the concrete appearance. The concrete surface layer change and static contact angel was tested for the review of application. The result of this study shows that the effective silicate is tetra ethyl ortho silicate and lithium silicate. The adhesion in tension is satisfied with performance requirement of KS standard but the reinforcement of concrete substrate is slight. So, The self-cleaning silicate concrete impregnant of this study is more desirable for the improvement of durability rather than the reinforcement.