• Journal of Pharmaceutical Investigation
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• v.28 no.2
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• pp.81-85
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• 1998

Three polymorphic modifications and two pseudopolymorphic modifications of cefotaxime sodium were obtained by crystallization from different organic solvents. The isolated crystal forms were characterized by UV spectrophotometry, DSC, TGA and X-ray crystallography. Crystal forms of cefotaxime sodium were also compared by dissolution rate. The dissolution rate of form 1 was the highest, followed by form 2, form 4, form 6, form 5 and form 3. Among these polymorphic modifications the dissolution rate of form 3 and form 5 was much slower than that of cefotaxime sodium on the market. All forms showed no change after 2-month storage test in the silica gel desiccator. But after the storage of 2-month at 95% relative humidity condition, all forms were deliquesced by hygroscopic property except form 1 that showed the highest dissolution rate. At 52% relative humidity condition, form 1, form 2 and form 6 had no evidence of phase transformation, but form 3, form 4 and form 5 were also deliquesced.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1785-1787
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• 2000

This paper present the result of the investigation, the electric properties of insulators due to non-soluble contamination. In general, the humidity and the amount of soluble salts such as NaCl, $MgCl_2$ are the most dominant factor. Though the non-soluble do not distribute on conductivity of contaminant layer, that has the hygroscopic property. For this study, we make a mini-fog chamber with transparent acryl and the kaoline was used for non-soluble contaminant. The kaoline was applied with sprayer to get the specific ESDD and NSDD value, then the specimen was dried and installed horizontally. And to measure the leakage current a DAS system was developed with LabView. With the result, we could know the influence of non-soluble content and the relationship between NSDD and ESDD.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.2
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• pp.1-9
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• 2009

Conductive adhesives have recently received a lot of focus and attention from the researchers in electronics industry as a potential substitute to lead-containing solders. Numerous studies have shown that the conductive adhesives have many advantages over conventional soldering such as environmental friendliness, finer pitch feasibility and lower temperature processing. This review focuses on the recent research trends on the reliability and property evaluation of anisotropic and non-conductive films that interconnect the integrated circuit component to the printed circuit board or other types of substrate. Major topics covered are the conduction mechanism in adhesive interconnects; mechanical reliability; thermo-mechanical-hygroscopic reliability and electrical performance of the adhesive joints. This review article is aimed at providing a better understanding of adhesive interconnects, their principles, performance and feasible applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.679-682
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• 2000

This paper present the result of the flashover properties of inulators due to artifitial pollution. For this study, a mini fog chamber has been fabricated with transparent acryl which has the merit in observasion and electrical insulation. All the experiment was carried in mini fog chamber. Though non-souble contaminant do not distribute on the electric conductivity of contaminant and contaminated insulator, that influence on the flashover characteristics of insulators. with the result, we assume phenomenon caused with the hygroscopic property of non-soluble contaminant.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.691-695
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• 2000

This paper present the result of the investigation, the electric properties of insulators due to non-soluble contamination. In general, the humidity and the amount of soluble salts such as NaCl, MgCl$_2$are the most dominant factor. Though the non-soluble do not distribute on conductivity of contaminant layer, that has the hygroscopic property. For this study, we make a mini-fog chamber with transparent acryl and the kaoline was used for non-soluble contaminant. The kaoline was applied with sprayer to get the specific ESDD and NSDD value, then the specimen was dried and installed horizontally. And to measure the leakage current a DAS system was developed with LabView. With the result, we could know the influence of non-soluble content and the relationship between NSDD and ESDD.

• Journal of Conservation Science
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• v.24
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• pp.13-22
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• 2008

The identification of species, hygroscopic property, and ability of ethylene gas absorption of 23 ancient charcoals excavated from wooden coffin burials and roof-tile kilns of Chudong-ri cultural site were investigated. All of the 12 charcoals excavated from wooden coffin burials were broad-leaved trees. Among the total 12 samples, 9 samples were Lepidobalanus and others were Celtis spp.. On the other hand, other 11 charcoals from roof-tile kilns were needle-leaved tree, Pinus spp.(hard pine). The broad-leaved tree charcoals from wooden coffin burials showed a higher moisture absorption capacity than needle-leaved tree charcoals from roof-tile kilns. The ethylene gas absorption was greater in the Lepidobalanus charcoal than that of Celtis spp. and Pinus spp. (hard pine) charcoal. The broad-leaved tree charcoal having high absorption ability of substances was due to a large microporous and specific surface area. Therefore, it was estimated that broad-leaved tree charcoals were filled in order to make favorable condition in tomb. The wood quality of pine is soft and easy to burn because of low specific gravity, as well as high calorific value by resin in wood. We could assume that the pine wood was used as fuel for roof-tile kilns because of easy control of heating and thermal power.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.124-127
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• 2001

In this study, the electrical properties of polymer thin film layered by spin-coating method was investigated, and this polymer is one of the polymer applied to insulation layer for display, this polymer has relatively high dielectric constant, hygroscopic property and easy to make thin film by spin-coating. That is, in this study use the polymer that is cyano acrylate terpolymer, and the MIM(Metal/Insulator/Metal) structures were fabricated to measure the electrical properties such as Voltage-Current characteristics and dielectric characteristics. Also the conductivity and dielectric constant has been calculated. As a result, the conductivity in room temperature was $0.85{\times}10^{-14}{\sim}1.35{\times}10^{-14}$[S/cm]. The fact that this polymer be acted as insulator can be supported by this result. The dielectric constant was calculated as $10.39{\sim}12.05$ higher than Dopont Inc., this make it possible to accumulate more charges in insulation layer under same condition.

• Journal of Sericultural and Entomological Science
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• v.43 no.1
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• pp.41-48
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• 2001

The purification, dissolution and powdering of stained waste silk obtained from weaving and dyeing process were studied for the surface modification of textile fabric and plastic materials. The whiteness of stained waste silk could be improved through degumming and bleaching with sodium hydrosulfite. The water-soluble fibroin solution can be obtained by dissoving the degummed waste silk in a boiling solution of 50% calcium chloride for 60 minutes. The salts and heavy metals contained in fibroin solution were removed by electric dialysis, wool fiber filtration and gel filtration chromatography. The fibroin powder was prepared by using a fine grinder after the alkali treatment for weakening the silk fiber. The fine fibroin powder of particle size around 30 ㎛ was obtained with a ultra fine-mill, while it was finer below 10 ㎛ with a ball-mill. The dissolved or powdered silk was applied to the surface of fabric with addition of the binder (a urethane resin). The moisture content of polyester and nylon fabrics treated with the silk solution was improved due to hygroscopic property of silk. The fine fibroin powder mixed with the binder ws coated on the surface of synthetic film by use of the air pressed sprayer. It was revealed that the hygroscopicity as well as the softness of fibroin powder coated film was much improved. Therefore, it is thought that the fine silk fibroin powder is applicable as an coating agent for the surface modification of plastic and synthetic leather.

• Applied Chemistry for Engineering
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• v.16 no.3
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• pp.361-365
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• 2005

Cement-reinforcing carbon fibers were surface-modified with $O_2$, $H_2O$, acrylic acid, diaminocyclohexane plasmas and their effects were investigated. Hydrophobic surfaces with water contact angles of $75{\sim}80^{\circ}$ were changed to hydrophilic surfaces. The water contact angles were reduced down to lower than $10^{\circ}$. As a result, the fiber's hygroscopic property and dispersion in water were improved. Also, Zeta potential of the fiber in water was changed from a negative value to positive values. As a result, adhesion with cement that had a negative Zeta potential was improved up to 57~124% through increased electrostatic interaction.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.341-347
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• 2006

Adsorption characteristics of benzene by zeolite were investigated using irradiating microwave. Experimental apparatus was applied to a U-type fix-bed column equipped with microwave system. Zeolite, itself, seems to be inappropriated to remove benzene because of a hygroscopic property, Microwave irradiation to zeolite, however, brings about decreasing $H_{2}O$ adsorption and increasing benzene adsorption. This causes that the dipole material such as $H_{2}O$ was vibrated and heated by irradiation of microwave and desorbed from zeolite. And then, benzene starts to be absorbed by zeolite. In this study, the results showed that the selective adsorption of benzene was occurred by the microwave irradiation and the adsorption capacity of benzene was increased by increasing microwave energy. As a results, it was found that the zeolite could be used to adsorb benzene with microwave and this method make it feasible simultaneously to adsorb and desorb benzene.