• Journal of the Korean Ceramic Society
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• v.45 no.10
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• pp.594-599
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• 2008

Hydroxyapatite(HA) was prepared from waste tuna bone, and its sintering property and dissolution behavior were investigated. Tuna bone derived-HA powder consisted of mainly HA and small amount of MgO. Porous HA ceramics with sintered density of 79% was obtained by pressureless sintering at $1200^{\circ}C$. Meanwhile, HA ceramics prepared by hot pressing at $1000^{\circ}C$ showed dense microstructure with sintered density of 95%. Immersion test revealed that both porous and dense HA ceramics were stable in liquid environment without distinct evidence of surface dissolution. It may be assumed that the presence of Mg in tuna bone-derived HA may improve dissolution resistance of HA.

• 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.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.437-444
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• 2017

In the composite waterproofing method in which a polyurethane coating waterproofing material is applied on the modified asphalt waterproofing sheet, the organic solvent is diluted in the coating waterproofing material in order to improve the workability. However, since the organic solvent is not volatilized before the curing of the polyurethane coating waterproofing material, the organic solvent causes dissolution of asphalt layer, thereby causing oil leakage. As a result, a polyamide film having a high dissolution resistance property was laminated on modified asphalt sheet, and through testing the dissolution resistance was visually confirmed and quantitative analysis of the polyamide film by SEM-EDX analysis was also used to confirmed the dissolution resistance of the polyamide film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.297-300
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• 2004

In this paper, we investigated insulation property of epoxy resin which includes elastomers to improve mechanical property, as varied to additive elastomer contents and to moisture absorption. There are four samples with 5[phr], 10[phr], 15[phr] and 20[phr]. we experimented to acquire insulation property(absorption rate, dissolution rate, apparent rate) and electrical property(perittivity, $tan\delta$, BDV) during respectively the time such as 6[h], 12[h], 18[h], 24[h] for moisture absorption. According to the experimental results, it is appeared that when the additive elastomer contents are increasing or when specimens remain more moisture, absorption rate, dissolution rate, permittivity and $tan\delta$ are slightly increasing but apparent rate and BDV(break-Down Voltage) strength are decreasing in particular, elastomer content [20]phr appeared remarkedly the more increase or decrease than others.

• Journal of Pharmaceutical Investigation
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• v.17 no.4
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• pp.175-181
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• 1987

To increase the dissolution rate of furosemide, chitin and chitosan which are widely occurring biodegradable natural materials were used as drug carriers. The ground mixtures of furosemide with chitin or chitosan were prepared by grinding in a ball mill. The ground mixture showed a faster and more enhanced dissolution rate than the physical mixture or intact furosemide. The crystalline peaks of furosemide disappeared in the ground mixtures indicating the production of amorphous form. The comparison of infrared spectra of the physical mixture and the ground mixture showed an interaction such as association between the functional groups of furosemide and chitin or chitosan in the molecular level. The weight losses in TGA curves showed all the same patterns. However, the endothermic peak due to the fusion of furosemide in DTA curve disappeared in the ground mixture indicating the different thermal property. The dissolution of furosemide from ground mixtures was fast in the order of chitosan and then chitin. The co-grinding technique with chitin or chitosan provided a promising way enhancing the dissolution rate of practically insoluble drug.

• Archives of Pharmacal Research
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• v.9 no.1
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• pp.55-61
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• 1986

To increase the dissolution rate of piroxicam, chitin and chitosan which are widely occurring biodegradable natural materials were used as drug carriers. The ground mixtures of piroxicam with chitin or chitosan were prepared by grinding in a ball mill. The dissolution rates of piroxicam from the ground mixtures were enhanced markedly than that from the physical mixtures or from intact piroxicam. The X-ray diffraction peaks disappeared in the ground mixture indicating the production of the amorphous form. The comparison of infrared spectra of the physical mixture and the ground minture showed an interaction such as association between the functional groups of piroxicam and chitin or chitosan in the molecular level. The weight losses in TGA curves shoed all the same patterns. However, in the ground mixture by DTA curve, the undothermic peak due to the fusion of piroxicam was disappeared indicating the different thermal property.

• Journal of Pharmaceutical Investigation
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• v.16 no.1
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• pp.36-41
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• 1986

The ground mixtures of ketoprofen with chitin or chitosan were prepared by grinding in a ball mill to increase the dissolution rate. The ground mixture showed a faster and more enhanced dissolution rate than the physical mixture or intact ketoprofen. The X-ray diffraction peaks indicated the production of the amorphous form of ketoprofen in the ground mixture. An interaction, in the ground mixture, such as association between the functional groups of ketoprofen and chitin or chitosan might occur in the molecular level. The endothermic peak due to the fusion of ketoprofen disappeared in the ground mixture indicating the different thermal property. The co-grinding technique with chitin or chitosan provided a promising way enhancing the dissolution rate of practically insoluble drug.

• KSBB Journal
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• v.31 no.4
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• pp.291-299
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• 2016

In this study, Indomethacin, the poorly water soluble drug, was selected and prepared dispersing oral disintegrating films according to the molecular weight of polyethylene glycol (PEG) which are sort of dispersing agents. Also the molecular weight and content of PEG were evaluated effect on the degree of dispersion, physical property and dissolution when making oral dispersing film containing indomethacin to find appropriate condition and suggested guidelines of making oral dispersing film. The appropriate dispersing ratio of the amount of surfactants and dispersing agent were 1% and 4%, also the stability dropped in the PEG molecular weight of 4000 or more. Drying time of oral dispersing film was $90^{\circ}C$ for 10 minutes to 12 minutes that dispersing film's property about flexibility, detachability were very good. The oral dispersion film's content used PEG 400 was $98.6{\pm}0.5%$ and the most uniform. As the molecular weight of PEG increased, dissolution time also increased. On the basis of evaluation parameter, PEG with 400~600 of molecular weight was selected as good dispersing agent in oral dispersing film. Therefore, it can be suggested guideline of preparation application study in oral dispersing film.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.5
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• pp.447-454
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• 2009

Electrolyzed reduced water was known as an alkaline solvent than piped water, natural water and mineral water etc. By means of reduction property, electrolyzed reduced water could dissolve a solute than other kinds of water without chemicals. In this study, serpentine dissolution in electrolyzed reduced water was investigated as a novel pre-treatment of serpentine which was a minerals for carbon dioxide sequestration. The elements (Ca, Si, Mg etc.) of serpentine were dissolved rapidly at early in the dissolvation then after some minutes the solubilities of serpentine elements showed stable state without abrupt changes. In spite of serpentine elements dissolution, chemical bondings and crystallographic structure of serpentine were not changed. It was explained that the dissolution mechanism of serpentine occurred from surface in electrolyzed reduced water and bulk structure sustained without collapse.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.6
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• pp.391-397
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• 2000

Addition of Ca element and nonequilibrium heat treatment which promotes shape modification of eutectic Si and ${\beta}$ intermetallic compound were conducted to improve the mechanical properties of Al-Si-Cu alloy. Modification of eutectic Si and dissolution of needle-shape ${\beta}$ intermetallic compounds were possible by nonequilibrium heat treatment in which specimens were held at $505^{\circ}C$ for 2 hours in Al-Si-Cu alloy with Fe. Owing to the decrease in aspect ratio of eutectic Si by the heat treatment of the alloy with 0.33wt.% Fe, the increase in elongation was prominent to be more than double that in the as-cast specimen. Dissolution of needle-shape ${\beta}$ intermetallic compounds in the alloy with 0.85wt.% Fe led to the improvement of tensile strength as the length of ${\beta}$ compounds decreased to 50%.