• 한국식품영양과학회지
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• 제24권4호
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• pp.619-624
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• 1995

Sesame protein concentrate(SPC) was prepared from defatted sesame flour(DSF) at several different pH(2.0, 7.0, 9.0, 11.0) for protein extraction. Some of their functional properties were determined in order to compare the effects of pH during preparation of concentrates. Compared with DSF, nitrogen solubility was markedly improved in all SPC, and SPC extracted at pH 11.0 showed the highest solubility at all pH leaves examined. Fatabsorption was increased in all SPC prepared, but water absorption was decreased as the extraction pH of protein increased. The emulsifying properteis and foaming properties of SPC were remarkably higher than DSF. As the extraction pH of protein was increased, the emulsion activity was also increased, but emulsion stability was decreased. SPC extracted at pH 7.0 showed the highest foaming capacity on the other hand, the highest foaming stability was shown in SPC extracted at pH 2.0. As the protein extraction pH increased, the viscosity of the protein solution was increased. SPC extracted at pH 11.0 showed highest viscosity at all protein concentrations tested.

• Journal of Korean Society for Atmospheric Environment
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• 제14권E호
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• pp.27-40
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• 1998

The solubility characteristics of organic compounds were studied in terms of the extraction efficiency as a function of the polarity of the organic solvent, and the acidity of water in urban aerosol samples collected in University of East Anglia (UEA), Norwich, England. The extraction efficiency of organic compounds were evaluated with respect to the organic carbon, -nitrogen and -hydrogen by means of a wide range of solvent which include polar and nonpolar organic solvents as well as acids and alkaline water. In addition, after being dissolved in aqueous solution, the aqueous chemistry of organic compounds were studied in terms of the organic metal complexes in aerosol, which were studied with oxalic acid, copper, and zinc. The results of this study indicate that solubility characteristics of organic compounds depend on the polarity of the solvents and the acidity of the solvents. In particular, some organic compounds are water soluble, even though they are much smaller than acetone soluble fractions. In the comparison between polar organic solvent extraction and non- polar organic solvent extraction, it can be thought that significant fraction of organic compounds analysed in the aerosol samples, are polar organic compounds because of the higher extraction efficiencies of organic compounds in polar organic solvent extraction than in nonpolar organic solvent extraction. Regarding the study of the oxalic -metal complexes, it can be thought that most oxalic acids are present in the form of oxalic -copper complexes in the aerosols collected at UEA.

• 한국지역사회생활과학회지
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• 제17권3호
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• pp.123-131
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• 2006

To compare the quality characteristics, chunggugjang was prepared with Bacillus subtilis NRLSI IV on the different inoculum levels$(10^2,\;10^4,\;10^6,\;and\;10^8 CFU/ml)$ and fermentation times(0, 12, 24, 36, and 48 hours). Although significant change in total nitrogen content was not found, the content of amino type, soluble and ammonia type nitrogen was generally increased according to the increase in fermentation time. Decomposition rate of nitrogen was also increased by fermentation time and nitrogen solubility was the highest value(62-75.9%) at 48 hour fermentation. In results of color changes, it was found that L and a value were decreased but there was no significant changes in b value as fermentation time was increased. In chunggugjang made with long fermentation time, hardness was decreased and relative viscosity of viscous substance was gradually decreased after little increase at initial fermentation time. The effect of inoculum level on hardness and relative viscosity were similar to that of fermentation time, i.e. the decrease of these at high inoculum level. In activity of V-GTP, 36 hour incubation could produce the highest value whereas no effect of inoculum level was found during fermentation except at 48 hour. In chunggugjang made with $10^2CFU/mL$ of Bacillus subtilis NRLSI IV, the content of glucose, sucrose, raffinose and stachyose was dramatically decreased at initial fermentation time and that of phytic acid, oxalic acid, citric acid, tartaric acid and malic acid was also decreased during fermentation, although the increase in acetic acid was found.

• Macromolecular Research
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• 제12권6호
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• pp.598-603
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• 2004

Cellulose nitrate (CN) composite membranes, containing cobalt porphyrin (CoP) complexes self-assembled within nanometer-sized rhenium clusters (ReCoP), have been prepared and their oxygen and nitrogen gas perme­abilities were analyzed. The solubility of ReCoP and the characteristics of the corresponding composite membranes were analyzed using a Cahn microbalance, FT-IR spectroscopy, wide-angle X-ray scattering, and differential scanning calorimetry. The nitrogen permeability through the CN composite membranes decreased upon addition of ReCoP and CoP, which implies that the presence of these oxygen carrier complexes affects the structure of the polymer matrix. The oxygen permeability through the composite membranes containing small quantities of ReCoP decreased, but it increased upon increasing the concentration. The oxygen gas transport was affected by the matrix at low ReCoP concentrations, but higher concentrations of ReCoP increased the oxygen permeability as a result of its reversible and specific interactions with oxygen, effectively realizing ReCoP carrier-mediated oxygen transport.

• 한국식품영양과학회지
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• 제27권6호
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• pp.1110-1116
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• 1998

To determine the optimum conditions for the enzymic hydrolysis against wheat gluten of high con centrations (6~14%, w/w, protein), a hydrolysis system combining weak acid pretreatment and enzymic hydrolysis was investigated. Alcalase showed the highest DH(degree of hydrolysis) of the tested proteases. After hydrolysis by alcalase, subsequently peptidases were applied for the better DH of the wheat gluten hydrolyzate. Peptidase NP2 showed the highest DH of the tested peptidases, but flavour zyme was shown for the lowest bitter taste of the resulting hydrolyzate. In order to minimize aggregation or gelling at higher initial substrate concentration during heat treatment, wheat gluten suspension was pretreated with possibly low concentrations of hydrochloric acid at 105oC for 1 hour, and then enzy matically hydrolysed with alcalase and subsequently with flavourzyme. Each required minimum concen tration of hydrochloric acid in the wheat gluten suspension of 6, 8, 10, 12, and 14%(w/w, protein) was 0.10, 0.15, 0.20, 0.225, and 0.275N, respectively. After the subsequent enzymic treatment by alcalase and peptidase NP2 for 24 hrs, the nitrogen solubility in the final wheat gluten hydrolysates was increased to 94.9, 86.4, 85.3, 89.3 and 95.0%, and their amino nitrogen content was increased to 2.87, 5.68, 7.34, 9.71 and 12.50mg/m, respectively.

• Applied Microscopy
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• 제44권2호
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• pp.79-82
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• 2014

Aluminum nitride (AlN) powder was easily synthesized by the direct nitridation of Al melt containing ~20 wt.% Mg catalyst and the nitriding behavior was investigated by thermodynamic calculation and through observations of electron microscopy and X-ray diffraction. The addition of Mg catalyst decreased the nitriding temperature below $1,000^{\circ}C$, which is comparable to the high nitriding temperature of $1,400^{\circ}C$ required in carbothermal method. It was caused by a significant increase of the solubility of nitrogen gas due to the increase of Mg catalyst in Al melt. The dissolved nitrogen gas met Mg catalyst and was transformed into metastable $Mg_3N_2$. Finally the metastable phase reacted with Al to AlN.

• 한국주조공학회지
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• 제23권3호
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• pp.147-152
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• 2003

질소 용해도가 낮은 ${\delta}$상으로 응고가 시작되는 16Cr-3Ni 계 스테인리스강의 응고시 질소기포 형성에 미치는 질소 함량과 냉각속도의 영향이 조사되었으며 이를 기반으로 질소 기포 결함이 발생하는 임계 질소 함량을 예측하는 방법을 제시하였다. 질소함량의 증가는 질소 기포 결함을 증가시켰으며, 냉각속도의 증가는 질소기포결함의 형성을 다소 억제 할 수 있는 것으로 조사되었다. 실험적으로 구한 Fe-16Cr-3Ni-9Mn 합금의 임계 질소 함량은 0.19wt%였으며, 임계 질소 압력은 평형응고로 가정한 경우 1.27atm, Scheil 응고로 가정한 경우에는 1.23atm으로 계산되었다. 질소 용해도를 증가시킬 수 있는 Mn 함량의 변화에 따른 임계 질소 함량의 변화를 예측하기 위하여 계산된 임계 질소 압력을 Fe-16Cr-3Ni-11Mn 합금에 적용하였으며 이를 통해 얻은 임계 질소 함량은 평형응고로 가정한 경우 0.25wt%, Scheil 응고로 가정한 경우에는 0.24wt% 로 예측되었다. 예측 결과의 타당성을 확인하기 위하여 Fe-16Cr-3Ni-11Mn 합금의 실험 결과와 비교하였으며, 일치하는 결과가 얻어졌다.

• Journal of Nutrition and Health
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• 제13권1호
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• pp.43-48
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• 1980

In order to identify the taste components of Kochuzang (red pepper paste), glutinous rice Kochuzang were prepared with addition of Saccharomyces rouxii and Torulopsis versatilis respectively. The nitrogen compounds were determined during the fermentation period at intervals and the amino acid components of 210 days aged glutinous rice Kochuzang were measured. Results are as follows; 1) The increment of amino-N and soluble-N of Kochuzang were increased remarkably during fermentation period untill 60 day but after that period, the increment was slowly changed. 2) Ammonia-N of Kochuzang was increased slowly during aging period but after that time, the amount was decreased slightly. 3) Amino-N ratio and Nitrogen solubility of 300 days aged Kochuzang were 23.71-25.38% and 54.12-56.19% respectively. 4) 17 Kinds of amino acid were identified at 210 days aged Kochuzang those were Lysine, Histidine, Arginine, Aspartic acid, Threonine, Serine, Glutamic acid, Proline, Glycine, Alanine, Valine, Methionine, Isoleucine, Leucine, Phenylalanine, Tryptophane and Tyrosine. 5) Total amino acids were 3.5-4.1% which consists of Glutamic acid, 0.95-1.05%, Aspartic acid, 0.63-0.65% and Serine, Proline, Alanine, Valine, Leucine were 0.22-0.28% respectively but Methionine, Histidine and Arginine were below 0.1%, and Tyrosine, Tryptophane and Phenylalanine existed in Kochuzang in small quantities.

• 한국식품과학회지
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• 제25권6호
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• pp.602-607
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• 1993

본 실험에서는 토양에서 분리한 호알카리성 Bacillus sp. 유래의 cyclodextrin glycosyltransferase(CGTase)를 이용하여 전분을 기질로 하였을 때 CD의 생산에 미치는 여러 조건을 고찰하였다. CD의 초기생성속도를 최대로 하는 기질의 최적 dextrose equivalent(DE)값은 10.5이었고 이로부터 CD 생산반응인 cyclization에 필요한 기질의 최적 DE값이 존재함을 알았다. 온도가 증가할수록 CGTase의 활성도는 급격히 감소하였지만 CD 생산속도와 수율은 온도에 따라 증가하였다. 이는 CD 생산반응중 CGTase는 기질과 결합하여 열에 대해 안정성이 증가하기 때문인 것으로 생각된다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2002년도 제18회 학술발표대회 논문초록집
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• pp.65-69
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• 2002

Unsteady vaporization of a droplet quiescent in a high pressure environment are studied with emphasis placed oil the modeling of equilibrium at vapor-liquid interface. Complete set of conservation equations for liquid and gas phases is numerically time integrated. Vapor-liquid interfacial thermodynamics are solved by f]ash equilibrium calculation method. The model was proper]y validated with experiment and the improvement in the solution accuracy was made. Vaporization of n-pentane fuel droplet in nitrogen background gas is examined. Effects of ambient gas solubility, property variation, transient diffusion, and multicomponent transport on the droplet vaporization are investigated systematically. High-pressure effects on the droplet vaporization is examined and discussed.