• 생명과학회지
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• 제20권1호
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• pp.17-21
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• 2010

Phytoextraction은 식물을 이용하여 환경 정화하는 phytoremediation의 일부분으로서 금속으로 오염된 토양을 정화하는 것이다. 토양에 존재하는 금속의 추출을 용이 하기 위해서 현재 다양한 킬레이트가 사용되고 있다. Phytoextraction이 경제적이고 친환경적인 장점이 있지만 고농도로 오염된 지역에서는 적용이 어려운데 이는 식물이 이러한 지역에서 살아남기 어렵기 때문이며 이러한 문제점을 해결하는 것이 본 연구의 목적이다. 연구 대상의 금속으로서 구리를 선택하였고, 킬레이트는 아미노산인 시스테인과 히스티딘, 작은 크기의 유기산으로서 citric acid, malic acid, succinic acid, oxalic acid, 그리고 ethylenediamine (EDA)를 선택하였으며, EDTA는 비교대상으로 본 연구에 사용되었다. 다양한 농도의 구리를 포함하는 배지에 식물을 키우면서 여러 킬레이트가 식물의 뿌리 성장에 미치는 영향을 분석하였다. 시스테인, 히스티딘, 그리고 citric acid은 식물의 성장을 억제하는 구리의 영향을 완화시켜 주었지만 EDA는 오히려 더 강화시켜 주었다. 또한 킬레이트의 식물성장에 대한 영향은 구리의 식물 내 흡수를 억제 또는 촉진에 의한 것이다. 따라서 구리의 식물성장억제를 완화시켜주는 시스테인, 히스티딘, 그리고 citric acid는 고농도의 구리로 오염된 지역에 식물의 성장이 가능하도록 사용될 수 있으며 EDA는 기존의 phytoextraction에 유용하게 사용될 수 있을 것이다.

• Applied Biological Chemistry
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• 제34권3호
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• pp.213-218
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• 1991

깍뚜기 절임중 절임액의 소금농도에 따른 침투된 무우에 소금농도 변화와 발효과정중 pH와 총산도 변화를 측정하고, 절임액에 $KCI,\;MgCl_2,\;CaCl_2$의 첨가와 발효과정중 $Na_2HPO_4,\;Na_3PO_4,\;Ca\;EDTA,\;NaNO_2,\;Sod.\;citrate$ 등 세 가지 혼합물을 만들어 첨가하였을 때 발효에 미치는 영향을 조사하였다. 또한 절임 깍뚜기 무우를 발효전 microwave로 $1{\sim}3$분 가열하여 발효속도를 비교하였다. 그 결과 깍뚜기의 절임시 절임액의 소금농도에 따른 소금의 침투속도는 절임시간(log t)과 침투된, 소금 양의 직선관계로 표시할 수 있었으며, 절임 소금물에 0.05 M의 KCI의 첨가는 깍뚜기 발효를 약간 억제시키는 효과가 있었음을 알 수 있었다. Microwave 열처리는 1 또는 2분 처리하였을 때 발효가 촉진됨을 보였으나 3분 가열한 것은 발효를 약간 억제시켜 주었다. 또한 발효과정중(약 PH 4.4) 무기 또는 유기산염의 혼합물을 $0.001\;M{\sim}0.01\;M$의 낮은 농도로 첨가하였을 때 발효억제효과가 뚜렷하였으며, 세 가지 혼합물중 $Na_2HPO_4,\;Na_3PO_4,\;NaNO_2,\;Ca\;EDTA,\;Sod.\;citrate$를 혼합한 것이 대조구에 비하여 첨가 후 pH4.0에 도달하는 시간이 6배 이상 연장되어 가장 높은 발효억제효과를 보였다.

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1613-1618
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• 2014

Perovskite-type oxides are promising oxygen carriers in producing oxygen-enriched $CO_2$ gas stream for oxyfuel combustion. In this study, a new series of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ (x = 0.2, 0.4, 0.6, 0.8) was prepared and used to produce $O_2/CO_2$ mixture gas. The phase, crystal structure, and morphological properties of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ were investigated through X-ray diffraction, specific surface area measurements, and environmental scanning electron microscopy. The oxygen desorption performance of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ was studied in a fixed-bed reactor system. Results showed that the different x values of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ have no obvious effects on crystalline structure. However, the oxygen desorption performance of $SrCo_{1-x}Fe_xO_{3-{\delta}}$ is improved by Co doping. Moreover, $SrCo_{0.8}Fe_{0.2}O_{3-{\delta}}$ synthesized via a new EDTA method has a larger BET surface area ($40.396m^2/g$), smaller particle size (48.3 nm), and better oxygen production performance compared with that synthesized through a liquid citrate method.

• 대한화학회지
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• 제33권3호
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• pp.304-308
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• 1989

Methyl Thymol Blue(MTB) 발색시약을 사용하여 $Lu^{3+},\;Eu^{3+},\;Sm^{3+}$ 및 $Pr^{3+}$ 원소의 흡수분광광도법에 의한 정량법을 확립하였다. ligand와 금속의 몰비는 1:1이었으며 Hexamethylenetetramine 완충용액으로 pH 6.5로 만들었을 때 MTB의 최대흡수파장은 440 nm이며 희토류-MTB 착물의 최대흡수파장은 610 nm로 나타났고 용액의 흡광도는 발색 후 7시간 정도까지 일정한 흡광도를 나타내며 $0{\sim}110{\mu}g/50ml$의 범위에서 Beer의 법칙에 따른다. phosphate, EDTA, citrate같은 리간드이온들은 희토류 -MTB의 흡광도에 크게 영향을 주며 각각의 희토류 원소분석의 선택성은 없다. 메틸알코올, 에틸알코올 및 아세톤 용매에서도 희토류-MTB 용액의 흡광도는 변하지 않았다. 몰흡광계수는 $1.2{\sim}2.0{\times}10^4mol^{-1}{\cdot}l{\cdot}cm^{-1}$이다.

• 한국축산식품학회지
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• 제43권2호
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• pp.331-345
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• 2023

The effects of pink inhibiting ingredients (PII) to eliminate the pink color defect in cooked turkey breast produced from presalted and stored raw ground turkey in the absence or presence of sodium tripolyphosphate (STP) were examined. Ground turkey breast was mixed with 2% sodium chloride and vacuum packaged. After storage for 6 d, ten PII were individually incorporated without or with added STP (0.5%) as follows: none (control), citric acid (CA; 0.1%, 0.2%, 0.3%), calcium chloride (CC; 0.025%, 0.05%), ethylenediaminetetraacetic acid disodium salt (EDTA; 0.005%, 0.01%), and sodium citrate (SC; 0.5%, 1.0%). Treatments were cooked at a fast or slow cooking rate, cooled, and stored before analysis. All PII tested were capable of lowering inherent pink color compared to the control (No STP: CIE a^* pooled day reduction of 23.0%, 5.2%, 12.6%, and 12.6% for CA, CC, EDTA, and SC, respectively; STP: reduction of 21.5%, 17.4%, 6.0%, and 18.2% for CA, CC, EDTA, and SC, respectively). For samples without STP, fast cooking rate resulted in higher CIE a^*. However, slow cooking resulted in more red products than fast cooking when samples included STP. Presalting and storage of ground turkey caused the pink discoloration in uncured, cooked turkey (CIE a^* 6.24 and 5.12 for without and with STP). This pink discoloration can be decreased by inclusion of CA, CC, EDTA, or SC, but incorporation of CA decreased cooking yield. In particular, the addition of SC may provide some control without negatively impacting the cooking yield.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.6-15
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• 2013

The influence of processing fluids and electrode spacing on the electrokinetic process was evaluated to remediate As-, Cu-, Pb-contaminated soil. Single and mixture of sodium citrate, EDTA and NaOH was used to investigate the metal extraction. EDTA for washing reagent showed the highest removal efficiency. Based on the extraction result, the electrode spacing (20, 40, 60 cm) on the electrokinetic process was investigated to remove the multi-metals from soil. The highest removal was observed at the experiment with 60 cm of electrode spacing, however, the correlation between electrode spacing and removal of metals was not clear. The electrode spacing influenced the amount of accumulated electro-osmotic flow. BCR sequential extraction showed that electrokinetic process removed the fractionation of metals bound to Fe-Mn oxyhydroxide.

• Environmental Engineering Research
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• 제18권3호
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• pp.139-143
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• 2013

This study was performed to examine the in vitro toxicities which are incurred due to the mobilization metals from standard reference material (SRM) 1648, fine ($PM_{2.5}$), and coarse ($PM_{10}$) particulate matter collected in Seoul metropolitan area. DNA single strand breaks of approximately 74% and 62% for $PM_{2.5}$ and for $PM_{10}$, respectively, were observed in the presence of chelator (EDTA or citrate)/reductant (ascorbate), as compared to the control by 2% without chelator or reductant. $PM_{2.5}$ induced about 40% more carbonyl formation with proteins in the presence of EDTA/ascorbate than $PM_{10}$. Therefore, more damage to biomolecules was incurred upon exposure to $PM_{2.5}$ than to $PM_{10}$. The treatment of a specific chelator, desferrioxamine, to the reaction mixture containing chelator plus reductant decreased the extent of damage to DNA to the level of the control, but did not substantially decrease the extent of damage to proteins. This suggests that different arrays of metals were involved in the oxidation of DNA and proteins.

• 한국식품영양학회지
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• 제22권1호
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• pp.20-28
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• 2009

According to traditional oriental medicine, only non-coagulated native deer blood is said to be effective, and coagulated deer blood is ineffective. Thus, a drying and tablet-producing method for deer blood was developed to maintain its physiological and therapeutic activity, and so that after drying, it can be redissolved and protected from coagulation. Proteases such as trypsin, pepsin, chymotrypsin, and aminopeptidase were added to the deer blood indicating that it coagulated in an hour, as shown by the reference. Wax gourd extract, which is high in protease, was added to the blood resulting in anticoagulation for 31 hours. Also, additions of 1% EDTA, 0.38% sodium citrate, 0.16% calcium oxalate, 1.2% ethanol, and 0.006% heparin to the deer blood resulted in anticoagulation for 1 hour, 4 hours, 2 hours, 1 hour, and 31 hours, respectively. In an experiment using 0.19% sodium citrate plus 1% wax gourd extract, and 0.006% heparin plus 1% wax gourd extract, anticoagulation was maintained for up to 72 hours. However, since heparin can not be used in food, the deer blood tablet was made with the addition of 0.19% sodium citrate and 1% wax gourd extract, followed by freeze drying. The dissolution rate for the tablet manufactured in this manner was 96.7%. And the dissolution rates for spray-dried deer blood, vacuum-dried deer blood, and marketed deer blood tablets were 85%, 81%, and 25.5%, respectively. The composition of the tablet produced from the freeze-dried deer blood was 56.4% protein, 18.7% lactose, 1.2% amino acids, 1.0% glucose, 0.7% lipids, 180 mg/100 g of iron, 13 mg/100 g of potassium, 39.1 mg/100 g of calcium, 480 mg/100 g of sodium, 368 mg/100 g of chloride, each.

• 한국식품과학회지
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• 제23권2호
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• pp.188-191
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• 1991

김치를 장기간 저장할 수 있는 방법을 찾고저 인산나트륨과 칼륨, 구연산염, 그리고 인산염 혼합물(CA-A), 인산염에 $NaNO_2$, BHA를 첨가한 혼합물(CA-B), CA-B의 BHA를 구연산염으로 대치한 혼합물(CA-C) 등 3가지 염의 혼합물을 김치발효 중반기에 첨가하여 이들의 발효 억제 효과를 조사하였다. 이들 염의 첨가농도는 $0.001{\sim}0.01\;M$ 범위였으며 김치의 발효는 $4{\sim}35^{\circ}C$에서 하였다. 그 결과 인산나트륨과 구연산염은 발효억제 효과가 뚜렷하였으나 인산칼륨은 별로 없었으며, 발효억제 효과의 순위는 $Na_3PO_4-Na_2HPO_4-sodium\;citrate-NaH_2PO_4-K_2HPO_4-KH_2PO_4$이었다. 한편, 염혼합물들의 효과는 CA-B-CA-C-CA-A의 순으로 CA-B가 가장 높았다. 항산화제를 제외 시켰던 CA-C는 김치의 pH $4.2{\sim}4.4$ 범위를 유지할 수 있었던 시간은$4{\sim}25^{\circ}C$ 온도범위에서 대조구에 비하여 약 6배의 연장효과가 있었다. 미생물 성장실험에서 총균수와 Leuconostoc mesenteroides의 번식이 현저히 감소함을 보여주었다.

• 한국표면공학회지
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• 제24권4호
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• pp.206-214
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• 1991

In the basic study of selective electroless Ni plating of Si wafers, plating rate and physical properties are investigated to obtain optimum conditions of contact hole filling. Si wafers are excellently activated in the concentration of 0.5M IF, 1mM PdCl2, 2mM EDTA at $70^{\circ}C$, 90sec. The optimum condition of Ni-B deposition on p-type Si wafers is 0.1M NiSO4, 0.11M Citrate, $70^{\circ}C$, pH6.8, 8mM DMAB. The main factor in the sheet resistences variation of films is amorphous and on heat treating matrix was transformed into a stable phase (Ni+Ni3B) at $300-400^{\circ}C$. But pH or DMAB concentration in the plating solution doesn't play role of heat-affected phase change.