• Archives of Pharmacal Research
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• v.14 no.4
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• pp.298-304
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• 1991

Isoprinosine, an antiviral agent with a bitter taste, has been clinically used up to a maximum of 4 g daily in 4-8 doses. In this investigation, isoprinosine was microencapsulated with ethylcellulose 22 cps, 50 cps and 100 cps by means of polymer deposition from cyclohexane through temperature change. Complete removal of cyclohexane from the microcapsules was necessary, since ethylcellulose-coated microcapsules obtained from cyclohexane medium were heavily solvated with cyclohexane and formed lumps even after drying. The displacement of cyclohexane by n-hexane during isolation of microcapsules (Method III) or the freezing of the anal-washed microcapsules before drying (Mothod II) provided the dried products which were more discrete microcapsules than those which were simply dried in the air overnight (Method I). Method III was especially the most effective procedure in preparing finer and more discrete microcapsules. The drug-release from microcapsules was influenced by the ratio of core to wall, the viscosity grade of ethylcellulose and the overall microcapsule size. The release rate was adequately fitted to both the first-order and the diffusion-controlled processes. It is therefore possible to design the release-controlled microcapsules with ethylcellulose of different viscosity along with various core to wall ratio.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.537-546
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• 1994

The physical characteristics of polymer modified asphalt depend on many parameters, such as, the polymer nature, polymer content and the asphalt properties. The objective of this study is to investigate the temperature susceptibility of polymer modified asphalt. The asphalts employed in this study were two different grades : a soft(200/300) grade and a hard(85/100) grade. And chlorinated polyethylene of two different characteristics were used : plastomer(Tyrin 2552) and elastomer(Tyrin CM0730). Temperature susceptibility of asphalt is a fundamental feature for characterizing asphalt and modified asphalt. It can be quantified by the penetration index(PI) and pen-vis number(PVN). These indices were obtained from the measurements of penetration and viscosity of the asphalt samples. For both of asphalts, the addition of the polymers increases the value of PI and PVN. Plastomer modified asphalt shows higher value of PI and PVN than elastomer modified asphalt. Soft grade shows more temperature susceptibility than hard grade at elevated temperatures.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.19-24
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• 2014

PURPOSES : The study objective was to evaluate rheology and physical properties of SBS-modified warm-mix asphalt (WMA) binders in comparison with hot-mix asphalt (HMA) binders. METHODS : Four different SBS polymers were used to prepare polymer-modified asphalt (PMA) binders, and three different warm-mix additives (WAD) were used to prepare a total of 12 WMA PMA binders. The kinematic viscosity was measured at 115, $135^{\circ}C$. The PG was determined using DSR and BBR. The pass/fail (P/F) temperatures for high and low PG grading were evaluated for HMA PMA and WMA PMA binders. RESULTS : PG 76-22 binders could be prepared by modifying the base binder (PG 64-22) using 4.5 wt% of SBS. The kinematic viscosity (KV) of SBS PMA was increased by 3 times higher than that of base asphalt. The SBS PMA with WAD showed 10% lower KV than that of the normal SBS PMA at $115^{\circ}C$ The high P/F temperatures showed almost no difference between HMA PMA and WMA PMA binders. The high P/F temperature showed very high correlations with KV ($R^2$ > 0.97). The result of SBS modification caused increase of low P/F temperature by $2.7^{\circ}C$ on average. CONCLUSIONS : Since the PMA with WAD showed 10% lower KV than normal (HMA) PMA at $115^{\circ}C$, reducing PMA mixture temperature down to a WMA level was possible in this study. The higher KV binders showed the higher P/F temperature. There was almost no change in high P/F temperature due to the use of WAD. The SBS PMA, showing an increased low P/F temperature, might show somewhat poorer performance at low-temperature, even though the lower PG grade was staying at the same level, i.e., $-22^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.846-855
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• 2002

Several soft white spring and winter wheat cultivars were evaluated by analyzing physicochemical properties such as Single Kernel Characterization System (SKCS), milling properties, Rapid Visco-Analyzer (RVA), mixograph pattern, and sugar-snap cookie-making potentialities. Results of SKCS revealed kernel hardness had a positive correlation coefficient with test weight $(r=0.497^{*})$ and near-infrared reflectance (NIR) hardness $(r=0.495^{*})$. SKCS kernel weight had a significantly high correlation of $r=0.942^{**}$ with SKCS kernel size. The test weight had significantly high correlations with straight-grade flour yield $(r=0.720^{**})$, break flour yield $(r=0.490^{*})$, flour ash content $(r=-0.781^{**})$, and milling score $(r=0.838^{**})$. The average RVA peak viscosity of the soft white winter wheat was higher (195.1 unit) than the soft white winter wheat varieties (135.7 unit). A correlation was found between RVA peak viscosity and swelling volume. Significant correlation coefficients were obtained among cookie properties, milling properties, protein content, and mixograph absorption. The cookie top grain score had a correlation coefficient of $r=0.447^{*}$ with swelling volume.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.2
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• pp.212-223
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• 2017

This research investigated the screen printing method for natural indigo dye on cotton fabric. We examined four types of thickening agents (arabic gum, guar gum, indalca, and CMC) based on their ability to retard the oxidation of natural indigo print paste while the paste remained on the screen frame. The results indicated that the retardation of arabic gum towards oxidation was the greatest among the four types of thickening agents. The highest K/S value of the printed cotton was observed with a dye concentration of 50g/L fermented indigo powder. The best printing results were obtained when the duration of dye efficiency was tested for the 10 minutes of the dye paste remaining on the screen with a thickening agent concentration of 26.56% that represented 530 cps viscosity. The test of colorfastness to washing and rubbing of the printed cotton resulted in grade 5, and the colorfastness to sunlight resulted in grade 4. Chinese traditional Naminwhapo printing was reproduced on cotton fabric using the natural indigo printing method derived from this study.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.3
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• pp.8-12
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• 2009

According to a previous study, talc as a coating pigment can improve the viscosity and the water retention of coating color, the compressibility of coating layer, and hence gravure printability. Talc is also well known for its larger particle size than other pigments, which implies that less binder may be need due to its smaller specific surface area. This study investigated the possibility of reducing binder content for matte grade paper. Coating color was prepared with the Cotalc-2000, which showed the best properties in the previous study. The binder content was varied and the effect of binder content on the physical properties of coated paper and the gravure printability was investigated. It was shown that binder content could be reduced when talc was used as a coating pigment. The reduction in binder content did not influence gloss, roughness and the print density of coated paper but showed improvement in paper porosity, compressibility and missing dot.

• Transactions of Materials Processing
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• v.25 no.6
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• pp.402-408
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• 2016

A manufacturing technology of carbon fiber composites with thermoplastic polymer pellets and continuous woven fiber was investigated using a compression molding process. To secure the impregnation of resin into the porosity of fabric the composite specimens were prepared with general injection-molding grade polypropylene pellets and low viscosity polycarbonate pellets. Tensile tests of polypropylene and polycarbonate composites were performed. Polycarbonate composites showed higher fracture strength than that of polypropylene composites because of the difference of matrix properties. However, the increase rate of strength was lower than that of polypropylene composites due to the difference of coherence between matrix and reinforcement. To investigate the effect of carbon fiber volume fraction on the fracture strength variation polypropylene composites with different volume fraction were compression molded and tensile tests were performed together. It was shown that the fracture strength of the polypropylene composites increased by 3.2, 5.4 and 6.9 times with the increase of carbon fabric volume fraction of 0.256, 0.367, and 0.480, respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.923-926
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• 2008

Currently more high flow and high performance concrete is used for construction of buildings in the world. However, when high flow and high performance concrete put high performance water reducing agent in quantity to improve flow, it has a negative effect on concrete structures since segregation arises from it though flow will be improved. There are naked-eye observation, coarse aggregate washing test, L Flow test for permeation among reinforcing rods and measurement of viscosity to judge concrete segregation resistance. However, it is difficult to apply them to practical affairs since they are very complicated and troublesome. Therefore, the study analyzed EIS dividing slump flow value into slump value, how to valuate concrete segregation resistance more easily, on the basis of the existing reference materials to propose EIS. As the results, in the event of high flow concrete, it is desirable that EIS value is prescribed to be less than 2.5 at the time of managing segregation. Also, at the time of prescribing EIS with performance, it is judged that it is desirable to manage segregation as less than 2.2 (Grade 1), 2.2$\sim$2.4 (Grade 2) and more than 2.6 (Grade 3).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.79-83
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• 2020

A photoelectric grain color sorter is commonly used in postharvest technology to detect and separate grains considered to be of good quality from those of poor quality based on color. In this study, the milled rice of Haedamssal cultivated under early transplanting conditions was evaluated using the color sorting device. Rice was classified according to standard grades of 64% for grade A, 18% for grade B, and 17.2% for grade C. By head rice ratio analysis, the milled rice of Haedamssal was recorded a grade A of 72.9%, representing a 24.5% improvement compared to the 48.4% of original grains. However, the grades B and C of Haedamssal rice were lower than those of original rice. In addition, grade A whiteness of Haedamssal rice was 45.3, which was lower than that of original grains. The color affinity redness was significantly lower in Haedamssal rice than in the screening control. No significant difference was found in the amylose and protein contents of rice before and after selection by the grain color sorter. In contrast, grain viscosity analysis revealed an increase in peak and final viscosities, while the consistence viscosity increased in low grade levels. Our results suggest that the photoelectric grain color sorter could improve the head rice ratio and palatability of early transplanted Hadamssal rice.

• Journal of the Korean Ceramic Society
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• v.35 no.6
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• pp.575-582
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• 1998

Sutiability of Jungsan clay shale dolomite sludge Anyang feldspar and alumina as raw materials for light-weight porous ceramics was examined. In order to find optimum manufacturing conditions compositions heating temperatuers and heating times were varied and their effects on physical properties were measured and bloating mechanism was investigated. Jungsan clay seems suitable as raw material to make the light-weight constructional materials with 5wt% of ANyang feldspar and alumina added in calcined clay (800$^{\circ}C$) having bulk density of 0.45g/cm3 water absorption of 1.34% and compressive strength of 85kg/cm2 rapid-heated at 1200$^{\circ}C$ for 30min. It is suggested that bloating mechanism depends on the difference of tem-peratures between the inside and outside in specimen the remained gases in interstices can bloat by the li-quid phase of surface with high viscosity and gas pressure at elevated temperature.