• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.217-227
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• 2000

The permalloy soft magnet was produced by powder injection molding process. Rheological characteristics of mixtures, debinding conditions and the magnetic properties of permalloy after sintering ware investigated. The permalloy soft magnet with a permeability of 14200 could be obtained by preparing a mixture with a powder loading of 65.4 vol.% and PP/PEG binder system, solvent extraction, thermal debinding and subsequent sintering at 1350 $^{\circ}C$ in hydrogen. The permalloy soft magnet sintered in hydrogen showed a 95 % of theoretical density and a magnetic induction of 13.2 kG at the applied magnetic field of 50 Oe

• Journal of Energy Engineering
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• v.20 no.1
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• pp.36-43
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• 2011

Plant biomass has been proposed as an alternative source of petroleum-based chemical compounds. Especially, aromatic chemical compounds can be obtained from lignin by depolymerization processes because the lignin consist of complex aromatic materials. In this study, kraft lignin, the largest emitted substance among several kinds of lignin in Korea, was used as a starting material and was characterized by solid-state $^{13}C$-Muclear Magnetic Resonance($^{13}C$-NMR), Fourier Transform Infrared Spectroscopy(FT-IR), Elemental Analysis(EA). The depolymerization of kraft lignin was studied at water-phenol mixture solvent in near critical region and the experiments were conducted using a batch type reactor. The effects of water-to-phenol ratio and reaction temperature($300-400^{\circ}C$) were investigated to determine the optimum operating conditions. Additionally, the effects of formic acid as a hydrogen-donor solvent instead of $H_2$ gas were examined. The chemical species and quantities in the liquid products were analyzed using gas chromatography-mass spectroscopy(GC-MS), and solid residues(char) were analyzed using FT-IR. GC-MS analysis confirmed that the aromatic chemicals such as anisole, o-cresol(2-methylphenol), p-cresol(4-methylphenol), 2-ethylphenol, 4-ethylphenol, dibenzofuran, 3-methyl cabazole and xanthene were produced when phenol was added in the water as a co-solvent.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1568-1572
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• 2002

A 152 day trial was conducted to see the effect of feeding naturally fermented wheat straw (FWS) with either energy, protein or energy protein supplements on the growth of buffalo calves. Twenty four male buffalo calves (10-12 months old) divided in 6 equal groups were individually offered FWS as sole roughage along with either conventional concentrate mixture (conc), maize grains (M), solvent extracted mustard cake (DMC), M-DMC mixture (50:50), deoiled rice bran (DRB) or uromol bran mixture (UBM) in 70:30 ratio. The digestibility of nutrients, nitrogen retention and nutritive value was maximum in FWS:UBM followed by FWS:DMC and FWS:Conc groups. Almost, all the blood parameters were observed well within the normal range except that of blood urea (FWS:UBM) and creatinine (FWS:DMC and FWS:DRB). The dietary combination in which FWS was supplemented with only conventional protein supplement like DMC proved to be highly efficient as far as live weight gain was concerned. FWS supplemented with energy-protein combination i.e. MDMC could also be used as complete feed for growing calves in comparison to conventional feeding system.

• YAKHAK HOEJI
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• v.42 no.6
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• pp.621-626
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• 1998

Cactus (Opuntia ficus-indica var saboten Makino) is a tropical or subtropical plant, which is widely used as folk medicine for burned wound, edema and indigestion. We previously found that the ethanol extract of cactus stem showed anti-inflanunatory action. This investigation was designed to isolate the active fraction of anti-inflanimatory action from cactus stem by solvent extraction and colunm chromatography. Carrageenan-induced paw edema in rats and acetic acid-induced writhing test in mice were used as animal models to search anti-inflammatory and analgesic activities. respectively. The ethanol extract of cactus stem was consecutively extracted with hexane, ethyl acetate, and n-butanol. The hexane fraction was the most effective in carrageenan-induced paw edema, and then was separated in colunm chromatography of silica gel by the elution with hexane/ethyl acetate mixture. The most effective fraction 1 was separated in a second colunm chromatography by eluting with hexane/diethyl ether mixture. The most effective fraction 1-5 was obtained, and separated in a third column chromatography by eluting with hexane/chloroform mixture. It produced the most effective fraction 1-5-1. Moreover, fraction 1-5-1 showed an inhibitory effect on acetic acid-induced writhing in the doses of 30mg/kg and 60mg/kg,p.o.,indicating that it also contained analgesic activity.

• KSBB Journal
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• v.23 no.4
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• pp.281-284
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• 2008

A simple and efficient microwave-assisted extraction procedure was developed and optimized for the extraction of paclitaxel from the plant cell cultures of Taxus chinensis. The biomass, immersed in a methanol-water mixture, was irradiated with microwaves in a closed-vessel system. The microwave-assisted extraction was compared with the existing conventional solvent extraction in terms of yield, extraction time, and solvent consumption. The use of microwave energy allows rapid recovery of paclitaxel from biomass and dramatically reduces extraction time and solvent usage compared to conventional solvent extraction. The paclitaxel was completely extracted from biomass by microwave-assisted extraction for 3 min at $50^{\circ}C$, for 6 min at $30^{\circ}C$ and $40^{\circ}C$, respectively.

• International Journal of Highway Engineering
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• v.17 no.4
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• pp.53-61
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• 2015

PURPOSES : The objective of this study is to evaluate the SDAR (solvent deasphaltene residue), which is obtained from the solvent deasphalting (SDA) process, as a pavement material. METHODS : The physical properties of the SDAR were evaluated based on its chemical composition, and asphalt mixtures with the SDAR were fabricated and used for the evaluation of mechanical properties. Firstly, the chemical composition of SARA (saturate, aromatic, resin and asphaltene) was analyzed using the TLC-FID (thin-layer chromatography-flame ionization detector). Moreover, the basic material properties of the asphalt binder with the SDAR were evaluated by the penetration test, softening point test, ductility test, and PG (performance grade) grade test. The rheological properties of the asphalt binder with the SDAR were evaluated by the dynamic shear modulus ($G^*$) obtained using the time-temperature superposition (TTS) principle. Secondly, the mechanical properties of the asphalt mixtures with the SDAR were evaluated. The compactibility was evaluated using the gyratory compacter. Moreover, the tensile strength ratio (TSR) was used for evaluating the moisture susceptibility of the asphalt mixtures (i.e., susceptibility to pothole damage). The dynamic modulus $E^*$, which is a fundamental property of the asphalt mixture, obtained at different temperatures and loading cycles, was used to evaluate the mechanical properties of the asphalt mixtures. RESULTS AND CONCLUSION : The SDAR shows stiffer and more brittle behavior than the conventional asphalt binder. As the application of the SDAR directly in the field may cause early failures, such as cracks on pavements, it should be applied with modifiers that can favorably modify the brittleness property of the SDAR. Therefore, if appropriate additives are applied on the SDAR, it can be used as a pavement material because of its low cost and strong resistance to rutting.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.192-192
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• 2009

We have successfully demonstrated the inkjet printing process to fabricate $Al_2O_3$ thick films without a high temperature sintering process. A single solvent system had a coffee ring pattern after printing of $Al_2O_3$ dot, line and area. In order to fabricate the smooth surface of $Al_2O_3$ thick film, we have introduced a co-solvent system which has nano-sized $Al_2O_3$ powders in the mixture of Ethylene glycol monomethyl ester and Di propylene glycol methyl ether. This co-solvent system approached a uniform and dense deposition of $Al_2O_3$ powders on the substrate. The packing density of inkjet-printed $Al_2O_3$ films is more than 70% which is very high compared to the value obtained from the films synthesized by other conventional methods such as casting processes. The characterization of the inkjet-printed $Al_2O_3$ films has been implemented to investigate its thickness and roughness. Also the dielectric loss of the films has been measured to understand the feasibility of its application to 3D integration package substrate.

• Journal of the Korean Applied Science and Technology
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• v.22 no.3
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• pp.219-227
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• 2005

Competitive solvent extraction of the mixure of alkali metal and alkaline earth cation from water into organic solvent containing the crown ether carboxylic acid and anlogous crown ether phosphonic acid was investigated as follows. The lipophilic group is found to strongly influence to the selective extraction in the mixed systems from only alkali metal cation for sym-(n-decyldibenzo)-16-crown-5-oxyacetic acid $\underline{1}$ to mostly alkaline earth metal cation for sym-bis[4(5)-tert-butylbenzo]-16-crown-5-oxyacetic acid $\underline{3}$. Monoethyl sym-(n-decyldibenzo)-16-crown-5-oxymethylphosphonic acid $\underline{2}$. and monoethyl-sym- bis]4(5)-tert-butylbenzo]-16-crown-5-oxymethylphosphonic acid $\underline{4}$ showed good selectivity for $Na^+$ over $Mg^{2+}$, the second extracted ion. Structural variation in the crown ether phosphonic acid somewhat was influenced to the extraction selectivity in the mixed systems. when variation of the ionized group is influenced in the mixed systems, the selectivity of $Na^+$ as the second extracted ion was much better crown ether carboxylic acid $\underline{1}$ than crown ether phosphonic acid $\underline{2}$, while the efficiency of $Na^+$ extraction was better $\underline{2}$ (83% total loading) than $\underline{1}$ (32%).

• Fire Science and Engineering
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• v.33 no.4
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• pp.9-15
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• 2019

The flash points of DMF based organic solvent mixtures used in the synthetic leather manufacturing process were measured. The test group was composed of seven types of solvent mixtures, which included DMF, toluene, and MEK. Each flash point was tested according to the international standard test methods of KS M 2010. The flash points were then predicted using some prediction models and compared with the measured data. From the analysis results, the binary mixtures with a mole ratio of less than approximately 0.7 showed that the measured values were under 25 ℃. This showed that the expectation for the flammable risk lowering effects due to the mixing of high flash point materials was reduced. In addition, the predicted values were evaluated using the average absolute deviation (A.A.D). The results showed that the Le Chatelier's models had an "A.A.D" of 1.95 ℃ and were the closest to the measured values.

• Journal of Pharmaceutical Investigation
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• v.29 no.4
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• pp.329-335
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• 1999

Clenbuterol, a selective ${\beta}_2-adrenergic$ receptor stimulant, has been introduced as a potent bronchodilator for patients with bronchial asthma, chronic bronchitis and pulmonary emphysema. For the purpose of developing a transdermal preparation for clenbuterol, we attempted to select an optimal solvent system and permeation enhancer among fatty acids and fatty alcohols which are known to accelerate the penetration of various drugs in permeation experiments using hairless mouse skin and Franz diffusion cell. Apparent partition coefficient of clenbuterol was increased as pH of buffer solution was increased and solubility of clenbuterol was increased as the percent of propylene glycol(PG) in buffer solution(pH 10) was increased. Permeability of clenbuterol from different buffer(pH 10)/PG solvent mixtures was decreased as the percent of PG in pH 10 buffer solution was increased and among the various enhancers studied, lauryl alcohol was found to be the most effective enhancer, increasing the permeability of clenbuterol approximately 76-fold compared with control. Lauryl alcohol$(0{\sim}2%)$ enhanced the permeability of clenbuterol concentration-dependently. In this study, the optimal solvent system for the penetration of clenbuterol was found to be 50/50 buffer(pH 10)/PG solvent mixture containing 2% lauryl alcohol.