• 한국식품영양과학회지
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• 제11권3호
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• pp.67-74
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• 1982

나무딸기 과즙으로부터 추출한 anthocyanin 색소의 안정성에 관하여 pH, 온도, 유기산, 무기염, 금속이온 등에 대한 영향을 검토한 결과 특히 유기산과 무기염에 의하여 농색화 효과를 나타내었고 또한 지속적인 안정성을 가지므로 이를 관찰하여 보고한다. (1) 상온에서 pH 1$\sim$7의 완충용액에 나무딸기 과즙 색소 anthocyanin을 가하였을 때 초기흡광도는 pH가 낮을수록 높았으며 7일간 저장 중 색소의 분해속도는 pH 1과 2가 과즙색소의 pH인 3.7보다 더 빨랐다. 총색소의 잔존량은 pH 7.0 에서 가장 낮았고 pH 3.7에서 가장 많았다. (2) 온도에 대한 영향은 $40^{\circ}C$에서 6시간 후 색소 잔존율은 약 28%, $5^{\circ}C$에서 약 70%로써 온도가 낮을수록 색소잔존율이 높았다. (3) 유기산 첨가시 흡광도 변화는 첨가농도 증가와 함께 색소액의 흡광도가 증대되었으며 그 순위는 formic acid>acetic acid>n-butyric acid>propionic acid로 나타났다. Formic acid의 농색화 효과는 40일 저장후 무첨가구보다 약 10.3배이며 tartaric acid 약 4배, malic acid 약 3.9배, citric acid 약 3.8배 등의 순으로 농색화가 관찰되어졌다. (4) 무기염 첨가농도에 따른 anthocyanin의 농색화 효과의 순위는 sodium perchlorate>sodium sulfate>sodium chloride>sodium phosphate, monobasic로 나타났다. (5) 금속이온에 의하여 색소용액은 저장 5일에 크게 감소되었으며 저장중 $Cu^{2+}$, $Al^{3+}$의 감소율이 가장 컸으며 $Fe^{2+}$은 비교적 감소율이 작았다.

• 한국식품과학회지
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• 제31권5호
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• pp.1211-1215
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• 1999

마늘을 물로 추출할 때 효소분해와 pH, 그리고 유기산, 유기 또는 무기염의 첨가가 추출액의 고형분 수율과 색에 미치는 영향을 조사하였다. 그 결과 상업적다당류 분해효소에 의한 가수분해는 고형분 수율을 $15{\sim}20%$ 증가시켰으나 녹변현상이 더 발생하였고 노란색과 밝기가 감소되었다. 추출시 pH의 조정은 수율에는 큰 영향이 없었지만, $4.4{\sim}5.0$의 범위에서 녹색의 강도가 증가되어 적절치 않았다. 여러가지의 염과 유기산의 첨가 결과, $CaCl_2$와 sodium oxalate, tartaric acid, phosphoric acid가 수율 향상에 효과적이었으며, $K_{4}P_{2}O_{7}$은 수율향상과 녹변방지에 효과가 있었다.

• 공업화학
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• 제22권5호
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• pp.526-531
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• 2011

본 연구는 이산화탄소 흡수성능을 향상시키기 위하여 아미노산에 알칼리금속을 함침시키는 것이다. 사용된 아미노산은 글리신이었으며, 알칼리성분 추가에 따라 pH가 11까지 증가하였다. 시험제조한 아미노산 염은 회분식과 연속식 흡수공정에서 이산화탄소의 포집능을 평가하였다. 치환된 금속종류에 따른 이산화탄소 흡수량은 Sodium Glycinate (Na-Gly) ${\geq}$ Lithium Glycinate (Li-Gly) > Potassium Glycinate (K-Gly) 순으로 나타났다. 흡수반응온도에 따른 $CO_2$ 흡수량 시험결과, $20^{\circ}C$에서는 알칼리금속을 함침시킨 아미노산 염이 1차 아민보다 약간 낮은 흡수능을 보였으나, 연속식 흡수반응기에서는 10% $CO_2$ 흐름에 대하여 반응기 내부온도가 상승하면서($40^{\circ}C$, $60^{\circ}C$) 아미노산 염의 흡수량 증가폭이 아민에 비하여 상대적으로 크게 나타났다.

• 한국응용과학기술학회지
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• 제9권1호
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• pp.1-6
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• 1992

New five N-acyl-N-methyl taurate and their sodium salts were synthesized by acylating sodium N-methyl taurate in water in the presense of inorganic alkali as a catalyst. Wherein acyl group is a straight-chain radical of 10 to 18 carbon atoms. These compounds were identified by infrared spectroscopy. Surface activities of these sodium N-acyl-N-methyl taurate including surface tension, Ross-Miles foaming powers, foam stabilities, emulsifying powers and detergency were measured respectively. Also critical micelle concentration(cmc) were evaluated. Consequently these anionic surfactants with long chain acyl amine showed good emulsifying power of O/W type and had a good detergence.

• 한국환경보건학회지
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• 제35권1호
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• pp.58-63
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• 2009

This study investigated improvement to sludge dewaterability and coagulation for sewage treatment plant sludge by using sodium hypochlorite solution (NaOCl), ferric sulfate [$Fe_2(SO_4)_3$] and zeolite. The specific resistance to filtration(SRF), chloride, pH and turbidity were used to evaluate the sludge dewatering behaviors. The results of study were as follows: By varying the amount of NaOCl added the optimum result in terms of enhancement for pretreatment occurred when 34 mg/l of NaOCl was injected. When the total solids concentration of the sludge was 10,000 mg/l, the optimum ferric sulfate dosage for the sludge dewaterability was 150 mg/l and the corresponding SRF was $1.7{\times}10^7sec^2/g$. It was observed that injecting zeolite into sludge was effective in improving the dewaterability of sludge.

• 대한화학회지
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• 제60권4호
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• pp.251-256
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• 2016

This paper describes the synthesis of alkali metal salts of urea (ureates) and their application to the direct preparation of 4-nitrosoaniline from nitrobenzene via nucleophilic aromatic substitution of hydrogen. Sodium and potassium ureates were readily prepared from the reaction of urea with sodium hydride, metal methoxides, and metal hydroxides. The effect of ureates as nucleophiles on the conversion of nitrobenzene to 4-nitrosoaniline was investigated and compared with that of a urea-metal hydroxide mixture. It was found that the ureates were superior for producing 4-nitrosoaniline owing to their higher thermal stability of the ureate. The ureate obtained from the treatment of urea with sodium hydride gave the highest yield for the preparation of 4-nitrosoaniline. The ureates generated from the reaction of urea with metal hydroxide also gave high yields of 4-nitrosoaniline. Catalytic hydrogenation of 4-nitrosoaniline afforded polymer-grade 1,4-benzenediamine in quantitative yield.

• Elastomers and Composites
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• 제14권1호
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• pp.7-12
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• 1979

Graft copolymerization of methlymethacrylate(MMA) onto sodium alginate(SA) aqueous solution by sodium metaperiodate$(NaIO_4)$ as an initiator was carried out with the variation of the reaction time, the reaction temperature and the concentrations of initiator and monomer. The results obtained were as follows: 1. SA was easily separated from the reaction mixture of homopolymer, graft polymer and sodium alginate ungrafted by the treatment of concentrated boiling $Na_3PO_4$, solution with the small amount of $Na_2SO_3$ to the mixture and then isolated as the acid form by acidifying the salts solution containing SA. 2. The amount of graft polymer was larger than that of homopolymer below $70^{\circ}C$ whereas above $70^{\circ}C$ the amount of homopolymer was larger. 3. The sum of each amount of graft polymer ana homopolymer was always increased with increase of the reaction time, the reaction temperature and the concentrations of initiator and monomer. 4. With increase of the concentration of initiator, the graft efficiency was increased below $70^{\circ}C$ while decreased above $70^{\circ}C$. 5. Graft copolymerization of MMA onto SA in aqueous solution was carried out without initiator.

• Journal of Animal Science and Technology
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• 제65권5호
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• pp.1065-1080
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• 2023

The solubility and structure of myosin and the properties of pork gel with NaCl, KCl, CaCl₂, and MgCl₂ were investigated. Myofibrillar proteins (MPs) with phosphate were more solubilized with NaCl than with KCl (p < 0.05). CaCl₂ and MgCl₂ showed lower MP solubilities than those of NaCl and KCl (p < 0.05). The α-helix content of myosin was lower in KCl, CaCl₂, and MgCl₂ than in NaCl (p < 0.05). The pH of pork batter decreased in the order of KCl, NaCl, MgCl₂, and CaCl₂ (p < 0.05). The cooking yield of the pork gel manufactured with monovalent salts was higher than that of the pork gel manufactured with divalent salts (p < 0.05). The pork gel manufactured with KCl and MgCl₂ showed lower hardness than that of the pork gel manufactured with NaCl. The solubility and structure of myosin were different with the different chloride salts and those led the different quality properties of pork gel. Therefore, the results of this study can be helpful for understanding the quality properties of low-slat meat products manufactured by replacing sodium chloride with different chloride salts.

• 약학회지
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• 제38권2호
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• pp.202-210
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• 1994

To investigate the feasibility of mucosal delivery of $[D-Ala^6]$ LHRH, a potent analogue of LHRH, enzymatic proteolysis of $[D-Ala^6]$ LHRH and inhibitory effect of medium chain fatty acid salts(MFA) were studied using rabbit mucosal homogenate. $[D-Ala^6]$ LHRH incubated in homogenates of rectal(RE), nasal(NA) and vaginal(VA) mucosa were assayed by HPLC. The degradation of $[D-Ala^6]$ LHRH followed the first order kinetics. The degradation products were found as $[D-Ala^6]$ $LHRH^{1-7}$(m-i), to a lesser extent, $[D-Ala^6]$ $LHRH^{1-9}$(m-ii) and $[D-Ala^6]$ $LHRH^{1-3}$(m-iii) by the method of amino acid analysis(PITC method). The formation of$[D-Ala^6]$ $LHRH^{1-7}$ was not inhibited by the addition of disodium ethylenediaminetetraacetic acid but inhibited by sodium tauro-24,25-dihydrofusidate, suggesting that endopeptidase 24.11(EP 24.11) cleaves the $Leu^7-Arg^8$ bond of $[D-Ala^6]$ LHRH and is the primary $[D-Ala^6]$ LHRH degrading enzyme. The patterns of $[D-Ala^6]$ LHRH degradation indicated that EP 24.11 exists in each mucosal homogenate with the order of RE>NA>VA. MFA significantly inhibited the proteolysis of $[D-Ala^6]$ LHRH. The addition of sodium caprate(1.0%) or sodium laurate(0.5%) to the each mucosal homogenate completely protected $[D-Ala^6]$ LHRH from the degradation.

• 멤브레인
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• 제17권2호
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• pp.93-98
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• 2007

The reliability of innovative membrane contactors technology (i.e. Gas/Liquid Membrane Contactors, Membrane Distillation/Crystallization) is today increasing for seawater desalination processes, where traditional pressure-driven membrane separation units are routinely operated. Furthermore, conventional membrane operations can be integrated with membrane contactors in order to promote possible improvements in process efficiency, operational stability, environmental impact, water quality and cost. Seawater is the most abundant aqueous solution on the earth: the amount of dissolved salts covers about 3% of its composition, and six elements (Na, Mg, Ca, K, Cl, S) account for more than 90% of ionic species. Recent investigations on Membrane Distillation-Crystallization have shown the possibility to achieve significant overall water recovery factors, to limit the brine disposal problem, and to recover valuable salts (i.e. calcium sulphate, sodium chloride, magnesium sulphate) by combining this technology with conventional RO trains. In this work, the kinetics of $CaSO_4{\cdot}2H_2O,\;NaCl\;and\;MgSO_4{\cdot}7H_2O$ crystallization is experimentally investigated in order to improve the design of the membrane-based crystallization unit.