• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.9
• /
• pp.1462-1466
• /
• 2014

In this study, an attempt was made to produce oat protein concentrates from defatted oat groat by alkali extraction. Independent variables formulated by D-optimal design were NaOH concentration (X1, 0.005~0.06 N) for extraction and precipitation pH (X2, pH 4.0~6.0), and the dependent variable was extraction yield (Y1, %). Experimental results were analyzed by response surface methodology to determine optimized extraction conditions. Extraction yield increased both with an increase in NaOH concentration of the extraction solution and when approaching a precipitation pH of 4.9, and NaOH concentrations were a major influencing parameter. Solubility of oat protein concentrates showed a minimum value (i.e., 0.1%) at pH 5 and increased substantially at pH values in the range of ${\leq}$ pH 3 or ${\geq}$ pH 7, reaching a maximum value at pH 11 (i.e., 76%). Regression equation coincided well with the results of the experiment. Optimized extraction conditions to maximize extraction yield were 0.06 N NaOH (X1) for extraction and pH 4.7 (X2) for precipitation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.7
• /
• pp.599-606
• /
• 2019

Most facilities that manufacture products made from the hazardous materials operate at high temperatures and pressures. Therefore, there is a risk of fire explosion. In particular, an explosion accident is a major risk factor for facilities with hazardous materials, such as oil, chemical, and gas. Propylene is often used in sites producing basic raw materials and synthetic materials by addition polymerization at petrochemical plants. To prevent an explosion in the business using propylene, the explosion range with the oxygen concentration was calculated according to the changes in temperature and pressure using an inert gas, carbon dioxide. In these measurements, the temperature was $25^{\circ}C$, $100^{\circ}C$, and $200^{\circ}C$ and the amount of carbon dioxide in the container was $1.0kgf/cm^2.G$, $1.5kgf/cm^2.G$, $2.0kgf/cm^2.G$, and $2.5kgf/cm^2.G$. The explosion limit was related to temperature, pressure, and oxygen concentration. The minimum oxygen concentration for an explosion decreased with increasing temperature and pressure. The range of explosion narrowed with decreasing oxygen concentration. In addition, no explosion occurred at concentrations below the minimum oxygen concentration, even with steam and an ignition source of propylene.

• Korean Chemical Engineering Research
• /
• v.57 no.6
• /
• pp.790-803
• /
• 2019

The dioctyl terephthalic acid (DOTP) process produces plastic plasticizers by esterification of terephthalic acid with powder in the form of octanol. In this study, the dust explosion characteristics of terephthalic acid directly injected into the manhole in the form of powder in the presence of flammable solvent or vapor in the reactor of this process were investigated. Dust particle size and particle size distribution dust characteristics were investigated, and pyrolysis characteristics of dust were investigated to estimate fire and explosion characteristics and ignition temperature. Also, the minimum ignition energy experiment was performed to evaluate the explosion sensitivity. As a result, the average particle size of terephthalic acid powder was $143.433{\mu}m$. From the thermal analysis carried out under these particle size and particle size distribution conditions, the ignition temperature of the dust was about $253^{\circ}C$. The lower explosive limit (LEL) of the terephthalic acid was determined to be $50g/m^3$. The minimum ignition energy (MIE) for explosion sensitivity is (10 < MIE < 300) mJ, and the estimated minimum ignition energy (Es) based on the ignition probability is 210 mJ. The maximum explosion pressure ($P_{max}$) and the maximum explosion pressure rise rate $({\frac{dP}{dt}})_{max}$ of terephthalic acid dust were 7.1 bar and 511 bar/s, respectively. The dust explosion index (Kst) was 139 mbar/s, corresponding to the dust explosion grade St 1.

• Journal of the Korean Chemical Society
• /
• v.37 no.7
• /
• pp.677-682
• /
• 1993

Polyacryloylcephalexine and polymethacryloylcephalexine were prepared by the reaction of polyacryloylchloride or polymethacryloyl chloride with cephalexine. The antimicrobial activities of these polymeric drugs were investigated by the common twofold dilution technique and the minimum inhibitory concentration (MIC) of polymeric durgs was also examined. Polyacryloylcephalexine revealed an excellent antibacterial activity against Micrococcus luteus ATCC 9341, Escherichia coli ESS, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Mycobacterium phlei IFO 3158, Klebsiella pueumouiae KCTC 1560, Escherichia coli KCTC 1039, Salmonella typhimurium KCTC 1925. Polymethacryloylcephalexine revealed an excellent antibacterial activity against Micrococcus luteus ATCC 9341, Klebsiella pueumouiae KCTC 1560, Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Mycobacterium phlei IFO 3158, Escherichia coli KCTC 1039, Escherichia coli ESS, Salmonella typhimurium KCTC 1925.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.11
• /
• pp.4649-4655
• /
• 2010

The aim of this study was to investigate the effect of flowing the industrial wastewater effluents into the K lake which is located in the A city on the eutrophication. The lake was modelled as a continuous stirred-tank reactor. Phosphorus and Chl-a concentration in the lake were calculated to $0.29\;/m^3$과 $4.0\;g/m^3$ at steady state, respectively. Those simulated concentrations were very close to the monitored mean concentration of the lake, indicating that the simulation could be used a tool for characterizing the lake. The non-steady state concentrations of the phosphorus and Chl-a were proposed as a function of time as well. Phosphorus loading ($L_p$) and depth to retention time ratio ($H/{\tau}w$) was calculated in order to analyze the current state of eutrophication. We proposed a strategy to change the lake from eutrophic to permissible oligotrophic state using a graph consisting of two variables, $L_p$ and $H/{\tau}w$.

• Korean Journal of Environmental Agriculture
• /
• v.11 no.3
• /
• pp.253-260
• /
• 1992

A photoresponse that results in organisms dispersing from a region of bright light. generally termed photodispersal, is frequently observed in some fishes notably including mud fish (Misgurunus mizolepis G${\"{U}}$NTHER). The primary assumption for this study was that the photodispersion may result from the behavioral strategies of fishes aimed to avoid illumination conditions that could injure the cells in skin tissues via photodynamic sensitization reactions. Here we present some preliminary results that seem to support this assumption : (1) the locomotive action of dark-adapted mud fish was triggered by the onset of illumination with light : (2) blue light (400-500nm) was much more effective in bringing about the locomotive activity than yellow (550-650nm) and red (650-800nm) lights : (3) two blue light absorbing pigments, which photogenerate activated oxygen species, were separated from the skin tissues of mud fish, one of these being identified as riboflavin.

• Proceedings of the KAIS Fall Conference
• /
• 2011.05b
• /
• pp.937-940
• /
• 2011

물/유기용매의 혼합용액에 키토산을 분산시키고 이 현탁액에 글리시딜 트리알킬 암모늄염, 글리시딜 아릴염 등의 에테르 시약을 상온에서 현탁상태로 반응시켜 4급화 키토산을 제조하는 새로은 방법을 개발하였다. 이 방법으로 합성한 결과 수득율이 90%이상이었으며 후처리과정이 필요없었다. 4급화 키토산의 균에 대한 최소저지농도(MIC)를 조사한 결과 E. coli O157:H7 균주의 MIC는 0.007%-0.01%(70-100ppm)로 추정되었고 V. vulnificus 균주의 MIC는 0.005%(50ppm)정도이고 V.vulnificus 균주의 MIC는 0.007%(70ppm)이었다. 작물에 대한 항균성을 알아보기 위하여 4N-키토산의 항균 활성만이 검정되었는데, 4N-키토산은 고추 역병균인 P. capsici에 대하여 가장 높은 항균 활성을 보여 4,000 ppm에서부터 키토산 무첨가 대조구에 비하여 항균활성을 보였으며 P. capsici보다는 약하지만 잿빛곰팡이병균 B. cinerea에 대하여도 약간의 항균 활성을 보이고 있어, 16,000 ppm에서는 항균서이 뚜렷이 나타났으나 고추 탄저병균인 C. gloeosporioides에 대해서는 16,000 ppm 이라는 높은 농도에서도 항균 활성을 전혀 보이고 있지 않았다.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.2
• /
• pp.183-187
• /
• 2000

Removal rate of nitrogen compound containing swine wastewater was 97 percent in case of high loading rate treatment of swine wastewater at studies for process development using soil microorganism. Minimum hydraulic retention time(HRT) for nitrification process was 11 days and solid retention time was 25 days. Nitrification was between 5 and 11 days but this time $NO_2-N$ was remained. Reactor condition was injured to nitrosomonas according to pH, $NO_2\;^--N$, and $NH_3\;^--N$ concentration but this condition was recover to pH controlling.

• The Journal of the Acoustical Society of Korea
• /
• v.23 no.1
• /
• pp.1-7
• /
• 2004

We developed SH-SAW sensors to detect protein molecules in liquid solutions applying a particular antibody thin film on the delay line of transverse SAW devices. The antibody investigated was human-immune-globulin G (HigG) to hold the antigens (anti-HigG) in the protein solution. We fabricated the sensor generating 100 MHz with the piezoelectric single crystal LiTaO₃. We measured the frequency change of the sensor by adding the anti-body concentration on SAM (self assembled monolayer) deposited on the Au layer. The sensor showed stable response to the mass loading effects of the anti-HigG molecules with the sensitivity up to 10.8 ng/ml/Hz at noise level 400 Hz below.

• Journal of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.464-470
• /
• 1987

7-Substituted 2-aminophenazine-5,10-dioxides were synthesized by the reaction of 4-aminophenol with 6-substituted benzofuroxan derivatives which had been obtained from aniline derivatives bearing methoxy, methyl, acetyl, and nitro group at the para position. 2-Aminophenazine-5,10-dioxide was also prepared by the reaction of 4-aminophenol with benzofuroxan. The antimicrobial activities of these phenazine dioxide derivatives were investigated in terms of minimum inhibitory concentration by the common twofold dilution technique. It was observed that the antimicrobial activity of the phenazine dioxides bearing electron releasing substituents was stronger than that of those bearing electron withdrawing substituents. From this result, it was concluded that the antimicrobial activity of phenazine dioxide derivative has a direct relationship with the electronic effect of the substituents.