• Journal of the Korean Wood Science and Technology
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• 제20권1호
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• pp.60-71
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• 1992

To investigate the delignification behaviour in solvolysis pulping process, Populus alba ${\times}$ glandulosa H. and Pinus Kuraiensis S. et Z. were cooked with p-cresol and vater solvent(2:8, 5:5, 8:2 v/v) at $175^{\circ}C$ for 9 cooking time levels(20, 40, 60, 80, 100, 120, 140, 160, 180, min). Pulp yield, residual lignin content, de lignification rate, decarborhydration rate were determined. Delignification behaviours were analyzed by TEM. 1. The p-cresol-water solvent cooking of P. alba ${\times}$ glandulosa showed good delignification at the solvent system which the mixture ratio of p-cresol and water were 2:8(v/v), while the cooking of P. koraiensis with the p-cresol and water mixture ratio of 5:5 was no good. 2. P. alba ${\times}$ glandulosa showed three step-delignification phenomena at the solvent system which the mixture ratio of p-cresol and water were 2:8(v/v) anti 5:5(v/v). But P. koraiensis showed a first order delignification reaction at the same mixture ratio of p-cresol and water solvent system. 3. In TEM micrograph obtained for the solvent system which the mixture ratio of p-cresol and water was 5:5(v/v), the partial delignification of the cell corner of P. alba ${\times}$ glandulosa and P. koraiensis were observed at 60min. of cooking time. Complete delignification at the cell corner of P. alba ${\times}$ glandulosa was observed at 160min. and that of P. koraiensis was observed of 180min. of cooking time. 4. In optical microscopic observation, fiber separation of P. alba ${\times}$ glandulosa occured at 120min. and that of P. koraiensis began at 140min. of cooking time. 5. At the solvent system which the mixture ratio of p-cresol and water was 5:5(v/v), middle layer on secondary wall($S_2$) and cell corner of P. alba ${\times}$ glandulosa were more selectively delignified than primary wall(P) and outer layer on secondary wall($S_1$). However P. koraiensis did not showed any difference in delignification between cell wall layers and cell corner.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 한국펄프종이공학회 2007년도 춘계학술대회논문집
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• pp.380-390
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• 2007

The purpose of this study is to make a functional Hanji treated with an oriental lacquer which has various functionalities. The raw oriental lacquer produced in China was used in this study This lacquer was diluted with ethanol and terpene in different solvent ratios. The diluted lacquer in the solvents had two layers. The upper layer was solvent soluble and the lower contained precipitates. Hanji was treated with the solvent solubles and the mixture containing precipitates, and then properties of the Hanji were evaluated. The oriental lacquer consisted of 25.04% of water, 60% of urushiol, 3.13% of nitrogen-containing compounds, and 5.66% of gum. The pH of oriental lacquer was 5.3 and the viscosity was 1680 cP. The average weight, thickness, and density of Hanji treated with oriental lacquer tended to gradually decreased as the lower concentration of lacquer was used and as the solvent soluble was treated. Tensile strength of the treated Hanji decreased when the diluted lacquer was used and Hanji treated with terpene dilutes at the ratio of lacquer to solvent of 1:5 (v/v) showed higher tensile strength than ones treated with ethanol dilutes. The folding endurance decreased as the less concentrated lacquer was used and the highest value was obtained when 1:40 (v/v) of lacquer to solvent ratio in both ethanol and terpene mixture. Absorption ratio was higher in the Hanji treated with ethanol mixture, treated with the lacquer in higher concentration, and treated with ethanol mixture. Hanji treated with ethanol dilutes at 1:20 (v/v) and the lower ratio of lacquer to solvent showed a hydrophobic property. Amount of the bound dye materials tended to be decreasing as the concentration of lacquer becomes lower and it was higher in Hanji treated with ethanol mixture than with terpene mixture. Color of Hanji treated with the solvent diluted mixture was Y to YR-type, whereas that of Hanji treated with raw oriental lacquer was Y-type, terpene

• Journal of Pharmaceutical Investigation
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• 제12권3호
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• pp.74-87
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• 1982

To evaluate the pharmaceutical aspects of solvent deposition method where drug is solvent deposited on the surface of excipients, a study has been made on dissolution characteristics of indomethacin solvent deposited on lactose and potato starch. In a solvent deposition system, the drug-to-excipient ratio and kind of excipient effect much on dissolution rates of indomethacin. The experimental results are as follows: 1) Lactose was shown to be superior to potato starch as excipients in indomethacin solvent deposited. 2) Total amount of indomethacin dissolved from solvent deposition systems at 30 minutes were enhanced about 5 to 23 times compared with that of pure indomethacin. 3) Increased dissotion amount of indomethacin from the solvent deposition systems were observed to be alike in the systems where the drug-to-excipient weight ratios were 1 : 5, 1 : 7 and 1 : 10.

• The Korean Journal of Ceramics
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• 제7권1호
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• pp.16-19
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• 2001

For the fast dry of the aqueous tape, the process which water was reaplaced by organic solvent was proposed. Socalled, it was the solvent washing dry. Three organic solvents (methanol, ethanol and acetone) were selected for the washing solvent. The weight loss of the washed tapes was measured to evaluate the dry rate of the tapes and dried tapes were examined the generation of the cracks with the variations of the organic solvent and the washing time. Methanol, ethanol and acetone were available organic solvents for this method. The tapes washed in methanol, ethanol and acetone were dried rapidly for twenty minutes. After thirty minutes, the weight losses were not found any more, The solvent of the lower surface tension can decreases the crack of dried tape. If solvent substitutes water completely, though it was fast dried, crack can be eliminated.

• Plant Resources
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• 제6권3호
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• pp.221-226
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• 2003

To improve industrial scale extraction method for extraction of icariin from Epimedium koreanum Nakai, the yields under different extracting conditions such as solvent, temperature, duration and solvent to plant material weight ratio were compared. Regarding extracting solution, highest extracts and icariin yield could be achieved when 10% EtOH was used. In case of plant material to extracting solvent ratio, no significant differences could be observed from 1/10 to 1/50, indicating 1/10 was the most efficient. Extracting temperature significantly affected extracts and icariin yields in that 9$0^{\circ}C$ increased the collected extracts and icariin contents up to 29.6% and 0.76%, respectively, compared to 27.2%, 0.33% at 7$0^{\circ}C$. The yield of extracts was less dependent upon extracting temperature compared to icariin yield. Regarding extraction time, 4 hr and 6 hr resulted in high extracts and icariin yield, respectively. We found extracting Epimedium koreanum Nakai in 10 times volume of 10% EtOH for 4 and 6 hr at 9$0^{\circ}C$ seem to be relatively efficient methods for extracts and icariin, respectively.

• Carbon letters
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• 제23권
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• pp.55-62
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• 2017

We report on the dispersion state of partially reduced graphene oxide (PRGO) in organic solvents, namely methyl ethyl ketone, ethyl acetate, methylene chloride, toluene, and xylene, by controlling the carbon to oxygen (C/O) atomic ratio of the PRGOs. A two-phase solvent exchange method is also proposed to transfer PRGO from water to an aprotic solvent, such as methyl ethyl ketone. We achieve relatively good dispersion in aprotic and non-polar solvents by controlling the C/O atomic ratio of the PRGOs and applying the two-phase solvent exchange method. There is an increase in the glass transition temperatures with the dispersion of PRGOs into amorphous polymers, in particular a $4.4^{\circ}C$ increase for poly(methyl methacrylate) and $3.0^{\circ}C$ increase for polycarbonate. Good dispersion of PRGO in a nonpolar polymer, such as linear low density polyethylene, is also obtained.

• Journal of Pharmaceutical Investigation
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• 제15권3호
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• pp.100-112
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• 1985

Dissolution characteristics of flurbiprofen solvent deposited on ${\alpha}-cyclodextrin$, ${\beta}-cyclodextrin$, lactose and corn starch were studied to evaluate the pharmaceutical aspects of solvent deposition method where drug was solvent deposited on the surface of excipients. In a solvent deposition system, the drug to excipient ratio and kind of excipient affect much on dissolution rates of flurbiprofen. The solvent deposition system formation was confirmed by scanning electron microscope. By increasing the amounts of matrix, it was possible to enhance the dissolution rate of flurbiprofen solvent deposition system. The amount of flurbiprofen dissolved from ${\beta}-cyclodextrin$ deposition system (1:10) at 60 minutes was enhanced 6.5 times in water and 28 times in simulated gastric juice compared with flurbiprofen alone. Flurbiprofen solvent deposited system (1:10) enhanced dissolution rate greater than inclusion complex and dispersion system.

• Journal of Biosystems Engineering
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• 제28권4호
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• pp.325-334
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• 2003

Pinosylvin, a stilbenoid phytoalexin, is a health ingredient to be extracted from pine leaves. In this study, ultrasonication-assisted extraction process for manufacturing extracts with high content of pinosylvin from pine leaves was investigated. As process and system variables, ultrasonic power, sonication time and solvent ratio were selected. According to the experimental results, the effective yield of pinosylvin increased with the increase of ultrasonic power and sonication time and the decrease of solvent ratio. When the ultrasonic power of 2400 W/L was added to the solution of pulverized pine leaves of 8 g per 1 L of a solvent for 10 minutes, yield of extracts and purity, effective yield and concentration ratio of pinosylvin were 0.3166 g/g, 0.7247 mg/g, 0.2294 mg/g and 23.0, respectively.

• Bulletin of the Korean Chemical Society
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• 제28권9호
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• pp.1493-1498
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• 2007

In this work, alkyl methacrylate-based microgels were synthesized by an experimental design method, and their sebum absorption characteristics were investigated. The results of fractional factorial experimentation indicated that the cross-linking agent content, solvent content, and stirring speed were the main parameters in the synthesis of the microgels. The suitable synthesis conditions were determined by the response surface design method. Through a study of the monomer and solvent effects, it was confirmed that the microgel shows the highest sebum absorption ratio when t-butyl methacrylate is used as a monomer or when acetone is used as a solvent. The optimal microgel synthesis conditions for cosmetic application were determined, and the resulting microgel had a mean particle size of 4.7 μm and a sebum absorption ratio of 435%.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 한국에너지공학회 1992년도 학술발표회 초록집
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• pp.113-114
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• 1992