• 한국광물학회지
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• 제1권1호
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• pp.15-19
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• 1988

In the process of re-checking the phase relations of the Pt-Sb system the previously reported Pt4+Sb phase did not occur. Instead, Pt34Sb7 phase with an average chemical composition (wt%) Pt 89.3, Sb 11.4, total 100.7, has been newly found to exist, and the formula Pt34Sb7 has been tentatively assigned to it, It is pale brownish grey to yellowish grey under refloecting microscope and non-bireflectant, VHN100=225 (206-243). X-ray powder patterns are (d(I/Io)): 2.318(100), 2.293(100), 2.110(30), 1.440(50), 1.390(15), 1.283(5), 1.203(70) and 1.192(40)$\AA$. They are indexable on the basis of tertragonal cell with $\alpha$=3.948(3), c=16.85(1)$\AA$. A question whether the tetragonal Pt34Sb7 is the new phase or a polymorph of the cubic Pt4+Sb phase remains unclear and awaits better X-ray diffraction, electron microprobe analysis and DTA for the Pt4+Sb phase. The Pt3Sb phase reported to be of tetragonal symmetry has been confirmed to exist. It is greyish yellow in air and in oil, very weakly bireflectant, and weakly anisotropic. VHN25=216 (183-240). Its X-ray powder data have been successively indexed on a tetragonal cell with $\alpha$=3.9455(7), c=16.959(5)$\AA$.

• 한국자동차공학회논문집
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• 제5권6호
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• pp.77-88
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• 1997

The heat rejection to coolant is a dominant factor for building vehicle cooling system such as radiator and cooling fan. Since the vehicle cooling system also has effects on fuel consumption and noise, the study of heat rejection to coolant has been emphasized. However, the study on heat rejection to coolant has been mainly focused on the field that related to the characteristics of combustion and localized heat loss. It is no much of use in design for the entire cooling system because it is focused on such a specific point. In this work, the heat rejection rate to coolant for four different engines are obtained to derive a simple heat transfer empirical formula that can be applied to the engine cooling system design, and it is compared with the other studies. Also, to observe effects of engine operation factors and heat transfer factors on coolant, we measured the metal temperature and the heat rejection rate. The heat rejection to coolant does not depend significantly upon the coolant flowrate, but mainly upon the amount of air fuel mixture and the air fuel ratio as long as the composition of coolant does not change. The reduction of heat rejection to coolant did not effectively improve the fuel consumption, but was mostly converted to raise the exhaust gas temperature and the oil temperature.

• Food Science and Biotechnology
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• 제16권4호
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• pp.549-556
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• 2007

The study was carried out to examine on the refiner discharge from Alaska pollock as a collagen resource by characterizing biochemical and functional properties of collagen. The refiner discharge from Alaska pollock surimi manufacturing was a good resource for collagen extraction according to the results of total protein, heavy metal, volatile basic nitrogen, collagen content, amino acid composition, and thermal denaturation temperature (TDT). TDT of acid soluble collagen from refiner discharge showed $20.7^{\circ}C$, which was similar to that of collagen from Alaska pollock muscle and was higher than that of collagen from Alaska pollock skin. TDT of acid-soluble collagen from refiner discharge was, however, lower than those of skin collagens from warm fish and land animal. Acid-soluble collagen from refiner discharge of Alaska pollock could be used as a functional ingredient for food and industrial applications according to the results of water and oil absorption capacities, and emulsion properties. In addition, if the thermal stability of the acid-soluble collagens is improved, collagen from refiner discharge from Alaska pollock could be more effectively used.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.413-415
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• 2000

Piezoelectric ceramics of PZT have been developed to apply for transformers in notebook. Use of piezoelectric ceramics in applications like piezoelectric transformers was made possible by the development of new materials with high electromechanical coupling coefficients and high mechanical quality factor. "Hard" ferroelectiric ceramics of complex composition based on lead zirconate titanate with Mn additive have been prepared. The perovskitic phase reaction of the oxides. The crucial role played by the intermediate mixing and grinding procedures in the assessment of the final properties of the material was investigated. Densification up to approximately the theoretical density value was achieved. The polarization was obtained by subjecting the samples at $30kVcm^{-1}$ poling electric field, in a silicon oil bath heated at $110^{\circ}C$. Their microstructural and morphological properties were checked by X-ray diffraction analysis and scanning electron microscopy. The optimized samples presented very high qualify and electromechanical coupling factors, together with small dielectric loss.

• 농업과학연구
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• 제40권3호
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• pp.227-235
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• 2013

This study was conducted to prove the effect of irradiation on lipases (lipase AK, lipase AH, lipase PS-D, Lipozyme TLIM, Lipozyme RMIM and Novozyme SP435) which were used for interesterification reaction using batch type reactor. Through such interesterification, structured lipid (1(3)-palmitoyl-2-oleoyl-3(1)-stearoyl, POS) was synthesized by lipase treated with irradiation at different doses (0, 3, 7, 14, 29 and 59 kGy) using canola oil, palmitic ethyl ester (PEE) and stearic ethyl ester (StEE). After the reaction, fatty acid composition of triacylglycerol (TAG) in structured lipid was analyzed to compare the lipase activity. The results showed that activity of the irradiated lipase AH, PS-D and Novozyme SP435 with certain dose (3 kGy) were slightly improved. Such change of lipase activity suggested that irradiation might affect on the interesterification properties. Especially, Lipase AK, Lipozyme TLIM and Lipozyme RMIM after at 3 kGy irradiation showed that content of stearic acid ($C_{18:0}$) was increased while palmitic acid ($C_{16:0}$) decreased in the interesterified products.

• 대한화학회지
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• 제15권2호
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• pp.55-63
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• 1971

In this study, several nickel catalysts for the steam-hydrocarbon reforming process were prepared from various nickel salt, magnesium oxide, alumina and kaolinite. The activity and strength of the catalysts were investigated. 1. The proper composition of the calcined catalysts are: NiO (5-15%)-MgO(10-20%)-$Al_2O_3$(10-40%)-Kaolinite(50-80%). 2. The admixed or cosedimented ingredients of the catalysts was pelletized and calcinated at 1000 or $1150^{\circ}C$. Calcination at $1150^{\circ}C$ for an hour was optimum. 3. The water to oil ratio (W/O) for reforming of hexane should be above 7 mole/mole. As the W/O increases, more carbon dioxide and hydrogen, but less carbon monoxide was produced. Also carbon deposition become lessen at higher W/O. 4. Maximum conversion had attained at about $850^{\circ}C$. As the reaction temperature increases, more carbon monoxide and hydrogen, but less carbon dioxide and lower hydrocarbon was produced. 5. The percent conversion at $850^{\circ}C$ was about 80%, using a catalyst which the nickel oxide content are 5%.

• 한국연초학회지
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• 제25권1호
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• pp.39-46
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• 2003

The essential oils from Burley 21 tobacco was isolated by using the SDE (Simultaneous Distillation & Extraction) apparatus coupled with gas chromatography and mass spectrometry analysis. Burley 21 tobaccos were divided and collected by six stages at intervals of five days during air-curing process. Air curing was conducted with horizontal hanging method in greenhouse settled by shading materials. 55 components were identified by comparisons of retention indices and mass spectral data, including 22 hydrocarbons, 6 alcohols, 3 aldehydes, 9 ketones and 15 miscellaneous compounds. Neophytadiene was the major components of the oils and almost all hydrocarbons were gradually decreased during air-curing process. Most of alcohols were also diminished, on the contrary, 1-pentanol and benzyl alcohol among them were increased. Aldehydes and ketones were increased during air-curing and especially, the concentrations of solanone, $\beta$-damascone, $\beta$-damascenone and megastigmatrienones were much increased. Indole level of miscellaneous compounds were continuously increased during air-curing of Burley 21 tobacco.

• Journal of Pharmaceutical Investigation
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• 제29권4호
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• pp.343-348
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• 1999

The purpose of this study is to prepare the controlled release adhesive patch containing naproxen. Pressuresensitive adhesive (PSA)-type patch was fabricated by casting of polyisobutylene (PIE.) and mineral oil in toluene. Membrane-controlled release (MCR)-type patch was prepared by the attachment of the controlled release membrane on the PSAtype patch. The membrane was mainly composed of Eudragit, polyethylene glycol(PEG) and glycerin. The drug release profile and skin permeation test with various patches were evaluated in vitro. The release of naproxen from PIE-based PSAtype patch with various loading doses fitted Higuchi's diffusion equation. However, the permeation of naproxen through hairless mouse skin from PSA-type patch followed zero-order kinetics. In MCR-type patch, thickness of controlled release membrane affected on the drug release rate highly. In the composition of membrane, the release rate was decreased as the ratio of Eudragit increased. The drug release from the MCR-type patch followed zero order kinetics. The permeation of naproxen through hairless mouse skin from MCR-type patch showed lag time for the intial release period and didn't fit the zero-order kinetics

• 약학회지
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• 제44권4호
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• pp.293-299
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• 2000

Biodegradable microspheres made from poly-lactide-co-glycolide polymers have been considered as a new delivery system for single-dose vaccine. Purified tetanus toxoid (TT) was encapsulated in poly-lactide(PLA) and poly-lactide-co-glycolide (PLGA) microparticles using a solvent evaporation method in a multiple emulsion system (water-in oil-in water). The morphology of 77-loaded microparticles was spherical and the suface of them was smooth. The particle size was in a range of 2-10. Protein loading efficiency was 68-97.8%. PLGA (85:15) microparticle showed the highest efficiency. Protein release pattern was influenced by polymer molecular weight and composition. The release rate of PLA(Mw 100,000) microsphere was higher than any other microspheres. In consequence of the hydrolysis of PLGA(50:50) microspheres, environmental pH decreased from 7.4 to 5.0. The PLA, PLGA (75:25) and PLGA (85:15) microshperes showed no significant pH change. The antigenicity or n in microshperes was assayed by indirect sandwich ELISA using equine polyclonal tetanus antitoxin for capture antibody and human polyclonal tetanus antitoxin for primary antibody. The antigenicity of TT in PLA (Mw 100,000), PLGA(50:50, Mw 100,000) and PLGA (75:25, Mw 73,300) after 30 days incubation showed 54, 40.9 and 76.7%, respectively.

• 한국식품영양과학회지
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• 제22권5호
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• pp.643-649
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• 1993

대두의 조성은 다른 두류나 곡류와는 달리 35~40%의 단백질, 15~20%의 유지 및 20~25%의 당을 함유하고 있다. 예로부터 대두는 두부, 간장, 된장과 같은 전통식품의 원료로써 넓게 쓰여져왔다. 초원심분리에 의한 대두 단백의 성분은 침강정수에 의해 2, 7, 11 및 15S의 4가지 주요한 성분으로 나타난다. 저당잔백질 중 중요한 2성분인 7S 및 11S globulin은 많은 연구자들에게 의해 분리되고, 특성이 알려졌다. 미생물 효소에 의해 제조된 응고물은 금속이온 및 산처리에 의해 만들어진 것보다 훨씬 조밀한 구조를 나타내었다. 효소작용으로 얻어진 curd는 식품재료로써 개발되어지고, 식품가공분야에서도 폭넓게 이용될 것으로 기대된다.