• Korean Journal of Food Science and Technology
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• v.10 no.2
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• pp.143-150
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• 1978

In our previous report (Korean J. Food Sci. Technol., 9, 123. (1977), functional properties of soyprotein isolates prepared from defatted soybean meal were studied. Using those properties soyprotein fibers, which may be acceptable as meat analogs, were prepared with protein spinning apparatus. Soyprotein can be converted into the suitable form for the spinning by denaturation with alkali (0.6%) and continuous fibers were spun by extruding spinning solution into an 20% NaCl-1 N acetic acid coagulating bath. The process for producing soyprotein fibers on a bench scale was described and break strength, break elongation and textural parameters of the fibers formed were evaluated. The possible scheme of formation of soyprotein fibers was discussed.

• Journal of the Korean Electrochemical Society
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• v.5 no.2
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• pp.57-61
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• 2002

In this study, the effect of ammonium chloride on the electrodeposition of CoP magnetic alloy film was investigated. The correlation between the electrodeposition condition and the magnetic properties was tried to elucidate by the electro- analytical tests such as cyclic voltammetry. It was observed that the magnetic properties of the films were varied extensively with the ammonium chloride contents in the solution. The reason why the magnetic properties of the films were varied with the addition of ammonium chloride was thought that the addition of ammonium chloride controlled the electrocrystallization of CoP kinetically by charge transfer and increased the grain size and the orientation factor. This may cause the variation of the magnetic properties of CoP films.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.347-352
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• 2005

The objectives of this paper are to study the characteristics of heat transfer and pressure drop in plate heat exchangers for absorption applications, and to quantify the effect of mass flow rate, solution concentration, and geometric conditions such as chevron angle on the heat transfer coefficient and pressure drop in the plate heat exchangers. The working fluid is $H_2O$/LiBr solution with the LiBr concentration range of 53.2 - 62.5 % in mass. The results show that the overall heat transfer coefficient increases linearly with increasing Re. The heat transfer rate increases with increasing the chevron angle while it does not significantly depend on the LiBr concentration. The pressure drop also increases with increasing the chevron angle. The effect of the chevron angle on the pressure drop is more significant than that of the concentration.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.354-357
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• 1974

The critical micelle concentration(CMC) of sucrose monostearate is determined between 20 and $40^{\circ}C$, and the effect caused by the addition of sucrose distearate on the CMC is also studied. It is found that, when both of monoester and diester are dissolved, the curve of surface tension of the solution versus the concentration shows a discontinuity at about 40 dyne $cm^{-1}$ of the surface tension. The discontinuity is interpreted as the associate formed between monoester and diester changes its surface orientation at this region.

• Clean Technology
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• v.7 no.4
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• pp.273-280
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• 2001

An absorber is a major component in the absorption refrigeration systems and its performance greatly affects the overall system performance. In this study, experimental analyses on heat transfer characteristics for removal of absorption heat in ammonia-water bubble mode absorber were performed. Heat transfer coefficients were estimated as the variations of input gas flow rate, solution flow rate, temperature, concentration, absorber diameter and height, and input flow direction. The increase of gas and solution flow rate affects positively in heat transfer. However, the increase of solution temperature and concentration affects negatively. Moreover, under the same Reynolds Numbers, countercurrent flow is superior to cocurrent flow in heat transfer performance. In addition, from these experimental data, empirical correlations which can explain easily the characteristics of heat transfer are derived.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.68-68
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• 2003

오늘날 형질전환동물의 생산과 같은 생명공학기술의 발달로 인하여 우리나라 재래산양은 그 모델동물로서 번식 생리학적으로 매우 중요한 가치를 지니고 있을 뿐만 아니라 고유의 유전자원 보존 측면에서도 산양복제와 같은 다양한 연구가 절실히 요구된다. 따라서 본 연구에서는 이러한 생명공학기술의 기초자료를 제공하고자 난포란의 활성화 방법과 단위발생란의 체외발달율을 조사하였다. 성숙한 미경산 재래산양을 공시동물로 하여 CIDR를 이용하여 발정동기화를 시켰으며, 과배란 처리는 FSH와 hCG를 이용하여 과배란 처리를 실시하였고 난포란의 회수는 외과적 방법으로 개복하여 난소의 난포로부터 난자와 난포액을 흡입하여 회수하였다 난포란의 활성화 처리는 전기자극법과 약물처리 방법을 사용하였으며, 전기자극방법은 DC 2.36㎸/cm, 17$\mu$sec 전압으로 1회 전기자극을 가하여 활성화를 유도하였으며, 약물처리법은 5$\mu\textrm{g}$/$m\ell$의 ionomycin 용액에서 5min, 1.9mM 6-DMAP용액에서 4시간동안 처리하여 활성화를 유도하였다. 단위발생란의 배양은 10% GS(goat serum)가 첨가된 M16 배양액과 10% FBS가 첨가된 TCM-199 배양액에서 난관상피세포와 6~7일동안 공배양을 실시하면서 체외발달율을 조사하였다. 활성화 방법에 따른 체외발달율은 전기자극 및 약물처리를 하였을때 분할율은 3.1% 및 67.9%였으며, 상실배 및 배반포로의 발달율은 0% 및 7.9%였다. 단위발생란의 체외 발달율은 10% GS가 첨가된 M16 배양액을 사용하였을 때 분할율은 68.0%였으며, 이중 12.0%가 상실배 또는 배반포로 발달하였다. 뿐만 아니라 10% FBS가 첨가된 TCM-199 배양액에 난관상피세포와 공배양을 실시하였을 경우는 72.0%가 분할하였으며, 이중 16.7%가 상실배 또는 배반포로 발달하였다. 이상의 결과로 볼 때 활성화 처리는 ionomycin과 6-DMAP 용액처리가 적합하며, 단위발생란의 체외배양은 보다 적합한 배양조건의 확립이 필요한 것으로 생각된다.

• Membrane Journal
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• v.15 no.2
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• pp.132-140
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• 2005

The effects of electrical fields on the efficiencies in ultrafiltration for protein separation were explored. The experiments were proceeded under constant transmembrane pressure (THP) using protein (albumin and lysozyme) solutions. For ultrafiltrations, cellulose membranes with molecular weight cut off (MWCO) 30 kDa were used. It is found that electrical field improved the filtration flux of albumin solution. The electrical field showed another interesting effect for filtration of protein solution. Depending on the electrical charges of protein molecules, the electrical field promoted or hindered the permeation of proteins through membranes. With the effect of electrical field, not only the permeation flux but also the selectivity of ultrafiltration could be improved.

• Journal of the Korean Electrochemical Society
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• v.11 no.4
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• pp.297-303
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• 2008

$LiNiO_2$ cathode powders with fine size have been synthesized by spray pyrolysis from the spray solution with citric acid and ethylene glycol. The as-prepared powders with spherical shape, porous structure and micron size turned into $LiNiO_2$ powders with micron size and regular morphology after post-treatment at $800^{\circ}C$. The initial discharge capacities of the $LiNiO_2$ powders changed from 199 to 171mAh/g when the concentrations of the citric acid and ethylene glycol added to the spray solutions were changed from 0 to 1 M. The maximum initial discharge capacity of the $LiNiO_2$ powders obtained from the spray solution with citric acid and ethylene glycol was 198 mAh/g when the lithium component added to the spray solution was 6 mol% excess of the stoichiometric amount. The discharge capacities of the fine-sized $LiNiO_2$ powders dropped from 198 to 163 mAh/g by the 30 th cycle at a current density of 0.1 C.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.558-558
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• 2012

최근의 원자간력현미경(AFM)은 soft한 생체물질을 비파괴적 방법 및 나노크기의 분해능으로 여러 구조적, 물리적 특성 측정이 가능하여 bio분야에 다양이 활용되고 있다. 본 연구에서는 AFM을 이용하여 줄기세포인 BM MSC(bone marrow mesenchymal stem cell)가 신경세포로 분화 여부를 측정하는 방법을 보고하고자 한다. 신경세포의 신호전달은 시냅스에서 신경전달물질을 매개로 하여 이루어지는데, 신경전달물질 중에 D-Glutamic acid는 시냅스후세포에서 흥분성 전위 크기를 증가시킨 상태를 장기간 유지시켜주는 물질로, 특정물질인 Glutamate와 항원-항체 결합을 한다. 본 연구에서는 이 두 물질간의 항원-항체 반응을 활용하여 줄기세포의 신경세포로 분화 여부를 AFM으로 측정하였다. 먼저, 수용성 시료인 두 물질을 증류수에 용해시켜 Mica 기판에 그 용액을 떨어뜨려 자연건조로 시료를 준비한 후, AFM으로 형태 및 크기를 측정하였다. D-Glutamic acid와 Glutamate는 구형 입자 형태를 보였으며, Glutamate의 너비는 ~100 nm이고, D-Glutamic acid는 ~50 nm였다. 두 물질이 든 용액을 섞었을 때, 항원-항체 반응에 의해 다른 크기의 두 구형입자가 붙어 있는 형태가 관찰되었다. 이 반응을 활용하여, 신경세포에서 분비되는 신경전달물질인 D-Glutamic acid를 선별하였다. DMEM 배지에 신경암세포주인 SH-SY5Y 를 접종한 후 $37.6^{\circ}C$의 incubator에서 24시간 배양하고, 화학적 자극(60~70 mM의 KCl 용액을 주입함)을 주어 신경전달물질 분비를 유도하였다. 그 배지에 항체 Glutamate 를 주입하여 자연건조 시킨 후 항원-항체 결합특성을 AFM으로 측정하여, 항원-항체 결합된 이미지와 동일함을 확인하였다. 결과적으로 AFM을 이용한 신경전달물질의 항원-항체 결합여부 측정을 통해, BM MSC 줄기세포의 신경세포로 분화를 판단할 수 있으며, 이 방법은 줄기세포의 특정 세포로의 분화 여부 판단에 활용될 것으로 기대된다.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.315-323
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• 1982

The measurement of cell constant in a diaphragm-cell method is the most important factor. In order to get the correct cell constant, the diffusion coefficients of potassium chloride were measured, at various concentration and temperature of potassium chloride solution, and at the stirring rate in the cell. The pseudo-binary diffusion coefficients of organic aroma component (benzaldehyde) in sugar solution has been measured at various concentration and temperature with the cell constant obtained above. Experimental results were compared and discussed with the semi-empirical epuations from literatures. And, especially, the diffusion coefficient of benzaldehyde, $D_{ba}$ for a small solute diffusing in a viscous solvent of larger molecules is proportional to the -0.82 power of the viscosity of aqueous sugar solution, ${\mu}$ at constant temperature, $D_{ba}{\mu}^{0.82}=constant$.