• 한국미생물·생명공학회지
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• 제27권2호
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• pp.91-95
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• 1999

To investigate the effect of salts on the production of erythritol by Torula sp., cells were grown on the media containing various concentrations of KCl or NaCl. Cell growth and glucose consumption rates decreased when KCl or NaCl concentration increased from 0.0 to 0.5M. The production of erythritol, however, was maximal at 0.3M aCl. The erythritol concentration of 54.3g/l in the medium containing 0.3M NaCl and 200g/l glucose was obtained after 120h. The production of erythritol decreased in cultures above 0.3M NaCl or 0.4M KCl due to the inhibition of cell growth. To elucidate the effect of salts more quantitatively, KCl and NaCl concentrations were converted to osmotic pressure. As the osmotic pressure increased, the yield of erythritol from glucose increased regardless of the kinds of salts and the yield of erythritol was approximately 49% at the osmolality of 2.4Os/kg. When the osmotic pressure increased to 2.5Os/kg, the specific growth rate of cells decreased but the production rate of erythritol increased. For the effective production of erythritol, osmotic pressure must be adjusted not to inhibit markedly the growth rate of cells and to stimulate the production rate of erythritol by supplementing salt.

• 한국환경농학회지
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• 제17권4호
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• pp.335-340
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• 1998

This study was conducted to determine the morphological responses of barley seedlings to NaCl stress and to investigate histological changes of cells with transmission electron microscope(TEM) after NaCl stress. Plant height and root length of 10-day old barley seedlings with NaCl stress were reduced and inhibition level was found to be more severe in the plant height than in the root length. The leaf length, leaf width and leaf area were shorter as well with NaCl stress than without NaCl stress. However, there was no difference in the number of roots between NaCl treatments. The weight of dry matter decreased at higher NaCl concentrations, especially at 100mM NaCl. The water content of shoots tend to decrease at higher NaCl concentrations, but there was no difference in the water content of roots, The reduced sugar content was greatly increase than starch. Cellulose content was higher in NaCl stressed-plant than control, and tended to decreased at higher NaCl concentrations. Lignin content also decreased NaCl stressed-plant but there was no tendency at NaCl stress concentrations. Electric conductivity of cell sap with seedlings was high with NaCl stressed-plant. Amount of cell sap gradually increased with time in the roots than in the shoots, The grana of chloroplasts was changed by 150mM NaCl concentration. The christe of mitochondria in root meristematic sells ruined in structure and cell wall of leaf and root was also ruined by NaCl stress.

• 생물환경조절학회지
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• 제19권4호
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• pp.317-323
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• 2010

본 연구는 염화나트륨과 염화칼슘 처리가 오이(Cucumis sativus L.) 접목묘의 도장억제에 미치는 영향을 살펴보고자 수행되었다. 오이 접목 후 염류의 처리 방법, 처리 시기 및 처리 농도를 diniconazole 처리구 및 무처리구와 비교하였다. NaCl을 저면관수나 상토에 혼입하여 처리한 경우 과도한 줄기신장이 억제되는 효과가 있었으며 묘의 충실도 또한 증가되었다. 하지만, 염화나트륨을 두상관수 처리할 경우에는 40mM 이상 농도부터 잎에 피해 증상을 나타낸 반면 도장억제 효과는 거의 없었다. 염화나트륨 처리시기를 접목 7일 후로 할 경우 접목 시에 처리하는 것 보다 도장 억제를 위해 더 높은 농도의 염화나트륨을 필요로 하였다. NaCl 처리 접목모종의 생육을 정식 후 36일에 조사한 결과, 대조구 대비 생체중의 변화는 없었으나 고온기 암꽃 수가 감소하는 경향을 보여 위험 부담이 따랐다. 전체적으로, 염화나트륨이 염화칼슘 처리보다 줄기 신장 억제에 더 효과적이었으며 잎에 나타나는 피해 증상도 적었다.

• 한국환경과학회지
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• 제9권3호
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• pp.253-259
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• 2000

The purpose of this study is to investigate the physicochemical characteristics of salinization of groundwater at the estern area of Cheju island. For this purpose, the major ions of groundwater, spring water are analyzed. The concentration of $Cl^-$ and Na^++K^+$/ contained in the groundwater at near the coastline are higher than those at inland area away from the coastline. The water quality components of groundwater observed at this area can be classified into 4 types such as Na-Cl, $HCO_3, Na-Cl-HCO_3$ and Ca-HCO$_3$. The concentration ratio of $SO_4^1 to Cl^- is 0.1354(R^2=0.972)$ at this area. This value is very similar with Dittomer's ratio of 0.13. For Na^+, K^+, and Mg^{2+}/ versus Cl^-$, their ratios also show a significant relationship between sea water and groundwater in this area. From the chloride-bicarbonate ratio, it can be estimated that the intrusion distance of seawater from coastline to inland area is 2.8km at Onpyung-Nansan, Sangdo and Pyungdae areas, and 5.4km at Kosung-Susan area. The mixing ratio between seawater and fresh water by the intrusion of seawater is decreased with the distance toward inland from coastline. This ratio(fresh water : seawater) is 80:20 in spring water adjacent the coastlines, Onpyung area and 99.8:0.2 in the well at No.3 of Susan located at inland away from the coastline. The concentration of $Na^+$ observed at field is 25~45% lower than that theoretically calculated by this mixing ratio. Based on the data of EC, the equipotential line of 500$\mu$mhos/cm is located at 4~5km poing at Kosung-Susan area and 2.5km point at the other area. The equation of correlation between $Cl^-$ concentration and EC values is $Cl^-$=0.1927EC-16.683 for the area lower than 500 $\mu$mhos/cm and $Cl^-$=0.2773EC for the area beyond 500 $\mu$mhos/cm.

• 동아시아식생활학회지
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• 제18권1호
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• pp.72-79
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• 2008

본 연구는 전란액에 sucrose, maltose syrup, dextrin을 첨가하고 달걀찜의 품질 특성을 알아보고자 하였으며, 관능검사를 통하여 달걀찜의 최적 NaCl 농도와 sucrose의 농도를 확인한 후 최적 NaCl 농도에서 sucrose 첨가가 달걀찜의 gel 형성에 미치는 영향을 알아보고자 하였다. 1. Sucrose의 첨가량에 따라 전란액과 달걀찜의 L, a, b값은 큰 차이를 보이지 않았으며, maltose syrup과 dextrin을 첨가한 경우에는 첨가량이 많아질수록 전란액과 달걀찜의 L, a, b값이 점점 감소하여 어두운 청록색 빛을 띠었다. 2. 기계적 texture에서는 sucrose 0.8% 첨가했을 때 급격히 쫀득해졌다가 sucrose 첨가량이 증가할수록 다시 연해지는 것을 알 수 있었으며, NF도 역시 sucrose의 0.8 % 첨가했을 때 가장 큰 값을 보이고 있어 가장 탄력이 있는 조직을 나타내는 sucrose 첨가량임을 알 수 있었다. Hardness는 sucrose 첨가 비율이 높아지면서 약간 감소하는 완만한 변화를 주고 있었다. Maltose syrup의 경우, 첨가량이 많아질수록 조직이 물러지고 SF도 현저히 감소하였으며, hardness는 maltose syrup의 첨가 비율이 증가하면서 감소하고 있는 것을 알 수 있었다. NF도 낮아져 maltose syrup의 첨가량이 많아질수록 조직이 약해지고 무르게 됨을 알 수 있었다. Dextrin을 첨가하지 않은 전란 달걀찜의 SF는 증가했다가 점차 감소하였으며, hardness와 NF는 dextrin의 첨가량이 증가할수록 점점 감소하여 조직이 약해지고 있음을 알 수 있었다. 3. 달걀액의 점도는 sucrose, maltose syrup, dextrin의 첨가량이 더해질수록 약간의 증가를 보이고 있었다. 4. 관능평가에 참가한 패널들은 0.8% NaCl을 첨가한 달걀찜의 짠맛을 가장 선호한다고 응답하였으며, 각 NaCl 농도 사이에 유의적인 차이가 있었다(p<.05). 전체적인 기호도에서는 최적 NaCl 농도인 0.8%에 0.3%의 sucrose를 첨가한 달걀찜에서 가장 선호도가 좋은 것으로 나타났으며, 각 시료간의 유의적인 차이가 있었다(p<0.05). 5. 최적 NaCl 농도0.8%에서 달걀찜의 색도는 sucrose 첨가량이 증가할수록 L 값은 어두워지고 있었으며, 최적 NaCl 0.8%에 sucrose의 첨가량을 달리한 달걀찜의 L, a, b 값이 각 시료 사이에서 유의적인 차이를 나타내었다(p<0.05). 최적 NaCl 농도 0.8%에 0.8% sucrose를 첨가해 제조한 달걀찜의 SF, NF, hardness메서 좋은 결과를 나타내었으며, NF에서 sucrose 첨가량을 달리한 시료 사이에 유의적인 차이가 나타났다(p<0.05). 이상의 결과로 부터 최적 NaCl 농도인 0.8%에 0.3%의 sucrose를 첨가해 제조한 달걀찜의 전체적인 선호도가 가장 좋은 것으로 나타나, 달걀찜 제조의 최적 조건임을 알 수 있었다.

• 공업화학
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• 제20권3호
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• pp.296-300
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• 2009

$RuO_2/Ti$를 양전극으로 사용한 무격막 전해셀(un-divided electrochemical cell) 시스템에서의 이산화염소수($ClO_2$) 제조 연구를 수행하였다. 이산화염소의 전구체로는 아염소산나트륨($NaClO_2$)이 사용되었으며, 무격막 전해셀에서 전구체 용액의 전해셀 주입유량, 전구체 용액 초기 pH, 아염소산나트륨과 전해질인 염화나트륨의 주입농도 그리고 전류밀도(current density)가 생성된 이산화염소수의 농도 및 pH에 미치는 영향을 조사하였다. 생성된 이산화염소수의 농도와 pH는 초기 전구체 용액의 pH와 전해셀 주입유량에 큰 영향을 받는 것으로 나타났으며, 전해질로 사용된 염화나트륨은 전해질로서의 역할 뿐만 아니라 이산화염소의 전구체로도 작용함을 알 수 있었다. 이산화염소수 제조를 위한 무격막 전해셀에서의 전구체용액의 최적 주입유량은 90 mL/min, 전구체 용액의 초기 pH는 2.3, 아염소산나트륨 주입농도는 4.7 mM, 염화나트륨 주입농도는 100 mM 그리고 전류밀도는 $5A/dm^2$로 나타났으며, 이때 발생된 이산화염소수의 pH는 약 3, 이산화염소 농도는 약 350 mg/L이었다.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.118-124
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• 2005

In this research, we examined the effect of NaCl on the growth, energy metabolism, and proton motive force of Halomonas salina, and the effect of compatible solutes on the bacterium growing in the high salinity environment. H. salina was isolated from seawater and identified by 16srDNA sequencing. The growth of H. salina was not enhanced by the addition of external compatible solutes (choline and betaine) in the high salinity environment. The resting cells of H. salina absorbed more glucose in the presence of 2.0 M NaCl than in its absence. H. salina did not grow in the medium with either KCl, RbCl, CsCl, $Na_2SO_4$, or $NaNO_3$, in place of NaCl. The optimal concentration of NaCl for the growth of H. salina ranged from 1.4 M to 2.5 M, and the growth yield was decreased in the presence of NaCl below 1.4M and above 2.5M. The activity of isocitrate dehydrogenase, pyruvate dehydrogenase, and malate dehydrogenase of H. salina was not inhibited by NaCl in in vitro test. The proton translocation of H. salina was detected in the presence of NaCl only. These results indicate that NaCl is absolutely required for the normal growth and energy metabolism of H. salina, but the bacterial growth is not enhanced by the compatible solutes added to the growth medium.

• Corrosion Science and Technology
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• 제18권6호
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• pp.312-317
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• 2019

The objective of this study was to investigate the corrosion behavior of aluminum (AA1100) in a mixed solution of 0 ~ 0.1 g/L Na₂S + 0.3 ~ 3 g/L NaCl + 0 ~ 10 mL/L H₂O₂. Potentiodynamic polarization tests were performed. Effects of solution compositions on corrosion potential, corrosion rate, and pitting potential of aluminum were statistically analyzed with a regression model. Results suggested that localized corrosion susceptibility of aluminum was increased in the solution with increasing concentration of NaCl because the pitting potential was lowered linearly with increasing NaCl concentration. On the contrary, H₂O₂ mitigated the galvanic corrosion of aluminum by increasing the corrosion potential. It also mitigated localized corrosion by increasing the pitting potential of aluminum. Na₂S did not exert a noticeable effect on the corrosion of aluminum. These effects of different chemical species at various concentrations were independent of each other. Synergy or offset effect was not observed.

• 한국전기전자재료학회논문지
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• 제23권12호
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• pp.1002-1006
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• 2010

In this study, magnesium (Mg), zinc (Zn) and aluminium (Al) as anode electrode and the solution of NaCl dissolved with 2~20 wt% as electrolytes were used for the metal-air cell. The open circuit voltage, short circuit current and I-V characteristics upon different kinds of anode electrode and electrolyte concentration were investigated. The open circuit voltage, initially about 1.45 V, rises to 1.6 V during the first 10 minutes indicating the necessity of an induction time to activate the catalyst on the air cathode. The short circuit current increases with an increased concentration of NaCl, causes an increase in the conductivity of the electrolyte solution, but the open circuit voltage did not under undergo influence of electrolyte. From NaCl 20 wt% electrolyte, the maximum output power of the magnesium electrode materials was measured with 177mW. It is found that the power characteristics of metal-air cell could be improved by using magnesium electrode materials in the NaCl electrolyte.

• 한국환경과학회지
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• 제18권11호
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• pp.1235-1245
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• 2009

The purpose of this study is to investigate electro-generation of free Cl, $ClO_2$, $H_2O_2$ and $O_3$ and degradation of Rhodamine B in solution using Ru-Sn-Sb electrode. Electrolysis was performed in one-compartment reactor using a dimensionally stable anode(DSA) of Ru-Sn-Sb/Ti as the working electrode. The effect of applied current (0.5-3 A), electrolyte type (NaCl, KCl, HCl, $Na_2SO_4$ and $H_2SO_4$) and concentration (0.5-2.5 g/L), air flow rate (0-3 L/min) and solution pH (3-11) was evaluated. Experimental results showed that concentration of 4 oxidants was increased with increase of applied current, however optimum current for RhB degradation was 2 A. The generated oxidant concentration and RhB degradation of the of Cl type-electrolyte was higher than that of the sulfate type. The oxidant concentration was increased with increase of NaCl concentration and optimum NaCl dosage for RhB degradation was 1.75 g/L. Optimum air flow rate for the oxidants generation and RhB degradation was 2 L/min. $ClO_2$ and $H_2O_2$ generation was decreased with the increase of pH, whereas free Cl and $O_3$ was not affected by pH. RhB degradation was increase with the pH decrease.