• 한국식품저장유통학회지
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• 제10권1호
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• pp.99-105
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• 2003

본 연구에서는 전기분해 격막 및 전해액에 따른 전해산화 수의 물리적 특성 및 미생물의 표면살균 효과를 검토하였다. 격막 방식의 전기분해수 제조 시스템의 최적조건은 간극이 1.0 mm 20% NaCl 첨가량이 6 mL/mm 일 때 제조된 전해산화수의 물성치가 ORP 1,170 mV 수준, HClO 함량 100 ppm 수준, pH 2.5 수준으로 가장 우수하게 나타났으며, 1단 방식보다는 2단의 전기분해 방식이 물성 측면에서 우수함을 알 수 있었다. 무격막 방식의 전해수는 간극이 1.0 mm, 20% NaCl 첨가량이 4 mL/mm 일 때 격막 방식의 최적 조건과 가장 유사하게 나타났으나 차아염소산 함량은 132∼266 ppm 수준, pH는 9 수준으로 격막 방식과는 크게 달라지는 것을 알 수 있었다. 전해산화수는 실온에서 밀폐 용기에 보관한 경우에 있어 격막 및 무격막 방식에서 각각 1,150 및 750 mV 수준, 100 ppm 수준을 1개월 이상 유지할 수 있었다. 격막 및 무격막 방식으로 제조한 전해산화수는 Salmonella typhimurium 등 12 균주가 초기 $10^{5}$∼$10^{6}$CFU/ml에서 30초 이내에 모두 사멸되는 것으로 나타났다. 전해액으로 NaCl 및 CaCl$_2$, KCl을 사용하여 제조한 전해산화수의 ORP 및 HCIO 함량은 NaCl, KCl, CaCl$_2$순으로 높게 나타났으나 큰 차이는 없었으며, 미생물 사멸효과는 동일하게 나타났다.

• 한국식생활문화학회지
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• 제15권2호
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• pp.95-100
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• 2000

This study was attempt to improve the quality of rapid- and low salt-fermented liquefaction of sardine (Sardinops melanoslicta). Effect of pretreatment methods such as water adding, heating, and intermittent NaCl adding on fermented liquefaction of chopped whole sardine were investigated. The divisions of the experimental samples by pretreatment methods were as follows; Sample A (water adding and heating): chopped whole sardine adding 20% water and then adding 3 and 5% NaCl consecutively at the intervals of 3 and 6 hrs during heating for 9 hrs at $50^{\circ}C$ and then fermented at $33^{\circ}C$ for 90 days. Sample B (preheating): chopped whole sardine with 8% NaCl and heating at $50^{\circ}C$ for 9 hrs and then fermented at $33^{\circ}C$ for 90 days. Sample C (control): neither pretreatment methods of water adding nor preheating on chopped whole sardine with 13% NaCl and then fermented at $33^{\circ}C$ for 90 days. Comparison of the appropriate fermentation period, yield of hydrolysate, chemical composition of fermented liquefied products were carried out. The highest content of amino nitrogen appeared at 60 days in the sample A, 75 days in the sample B, and 90 days in the sample C during the fermentation period. The appropriate fermentation period of the sample A was shorten 15 days than the sample B and 30 days than the sample C in the processing of sardine. The product A was lower NaCl (8.5%) and lower histamine content (25mg/100g) than the sample B and C. Possibly, three kinds of pretreatment methods such as water adding, heating, and intermittent NaCl adding, might be recommend as the processing of rapid- and low salt-fermented liquefaction product of chopped whole sardine.

• Corrosion Science and Technology
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• 제12권1호
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• pp.12-26
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• 2013

This work focused on galvanic corrosion of carbon steel bolted GECM/Al plates by long-term test in tap water and NaCl solutions. Test product was carbon steel bolted between cross packed GECM and painted aluminium. Tests for the product and coupled parts determined corrosion rate in tap water and NaCl solutions. Also, using a potentiostat and salt water sprayer, galvanic test was done. In galvanic test on carbon steel bolted GECM/Al plates, corrosion of carbon steel bolt was faster in series of tap water>1% NaCl solution>3.5% NaCl solution. In galvanic couple between aluminium and carbon steel bolt, their corrosion rates were higher than those of single specimen. In galvanic couple between GECM, aluminium, and carbon steel bolt, corrosion behaviors of carbon steel bolt and aluminium were changed due to different corrosion mechanism in tap water and chloride solution.

• Elastomers and Composites
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• 제45권2호
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• pp.100-105
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• 2010

EPDM 소재를 공기 중, 수돗물, 3차 증류수, NaCl/$CaCl_2$ 혼합 수용액, $CaCl_2/FeCl_3$ 혼합 수용액에서 7일간 노화시켰다. 노화 온도는 $90^{\circ}C$였다. 공기와 3차 증류수에서 노화된 시험편은 백화가 발생하지 않았으나, 수돗물, NaCl/$CaCl_2$ 혼합 수용액, $CaCl_2/FeCl_3$ 혼합 수용액에서 노화된 시험편은 백화가 발생하였다. 백화 물질을 규명하기 위해 GC/MS를 이용하여 가용성 유기물을 분석하였으며, 영상 분석기와 SEM을 이용하여 표면 형태를 조사하였으며, EDX를 이용하여 표면 적층물의 원소 분석을 실행하였다. 백화의 주요 원인으로는 금속 이온과 지방산과의 반응에 의한 지방산 금속염의 형성을 들 수 있다.

• 한국표면공학회지
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• 제39권6호
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• pp.282-287
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• 2006

Viscosities of $LaCl_3-NaCl$ binary melts were measured by the capillary method over the range of their liquidus temperatures to about 1200K. The cell constant were determined by using pure water. The results obtained are summerized as follows: Viscosities were decreased with the content of NaCl for all over the composition range of binary melts. Composition - viscosity relation for the binary melts show a non-linear from the additivity line and the deviations shows a maximum at about 60 mol% NaCl. This suggests the existence of the complex ion of $LaCl_4^-$ in the melt. Activation energy for viscous flow of the binary melts decrease monotonously with the increasing content of NaCl.

• 한국환경과학회지
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• 제26권5호
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• pp.563-572
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• 2017

The Electrocoagulation-Flotation (ECF) process has great potential in wastewater treatment. ECF technology is effective in the removal of colloidal particles, oil-water emulsion, organic pollutants such as microalgae, and heavy metals. Numerous studies have been conducted on ECF; however, many of them used a conventional plate-type aluminum anode. In this study, we determined the effect of changing operational parameters such as power supply time, applied current, NaCl concentration, and pH on the turbidity removal efficiency of kaoline. We also determined the effects of different electrolyte types (NaCl, $MgSO_4$, $CaCl_2$, $Na_2SO_4$, and tap water), as well as the differences caused by using a plate-type and mesh-type aluminum anode, on the turbidity removal efficiency. The results showed that the optimal values of ECF time, applied current, NaCl concentration, and pH were 5 min, 0.35 A, 0.4 g/L NaCl in distilled water, and pH 7, respectively. The results also revealed that the turbidity removal efficiency of kaoline in different electrolytes decreased in the following sequence, given the same conductivity: tap water > $CaCl_2$ > $MgSO_4$ > NaCl > $Na_2SO_4$. The turbidity removal efficiency of the mesh-type aluminum anode was significantly greater than the plate-type aluminum anode.

• Membrane and Water Treatment
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• 제2권3호
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• pp.147-158
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• 2011

Membrane distillation process was used for desalination of hot (333 K) geothermal water, which was applied in the plant producing heating water. The investigated water contained 120 g salts/$dm^3$, mainly NaCl. The mineral composition was studied using an ion chromatography method. The obtained rejection of solutes was closed to 100%, but the small amounts of $NH_3$ also diffused through the membrane together with water vapour. However, the composition of obtained distillate allowed to use it as a makeup water in the heating water system. The geothermal water under study was concentrated from 120 to 286 g NaCl/$dm^3$. This increase in the solution concentration caused the permeate flux decline by a 10-20%. The geothermal water contained sulphates, which was subjected to two-fold concentration to achieve the concentration 2.4-2.6 g $SO{_4}{^{2-}}/dm^3$ and the sulphates then crystallized in the form of calcium sulphate. As a results, an intensive membranes scaling and the permeate flux decline was observed. The XRD analysis indicated that beside the gypsum also the NaCl crystallites were deposited on the membrane surfaces. The fresh geothermal water dissolved the mixed $CaSO_4$ and NaCl deposit from the membrane surface. This property can be utilized for self-cleaning of MD modules. Using a batch feeding of MD installation, the concentration of geothermal water was carried out over 800 h, without significant performance losses.

• 생태와환경
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• 제46권3호
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• pp.388-394
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• 2013

염(NaCl) 스트레스 하에서 근대의 이온축적 및 삼투조절물질로 알려진 Glycine betaine (GB) 함량 변화를 알아보기 위하여 0, 100, 200, 300 및 400mM의 염(NaCl)을 처리하여 생장, 이온양상 및 GB 함량을 조사하였다. 염(NaCl) 농도와 처리시간이 증가함에 따라 근대 잎의 건중량은 염(NaCl) 0, 100 그리고 200 mM은 큰 변화를 보이지 않았으나 300 mM 이상의 염(NaCl) 농도에서는 감소하는 경향이 나타내었다. 양이온 함량은 염(NaCl) 농도 및 처리시간이 증가함에 따라 증가하였으며, 주로 $Na^+$ 이온을 축적하며 $K^+$, $Mg^{2+}$, $Na^+$, $Ca^{2+}$ 그리고 $Fe^{2+}$ 순으로 식물체 내에 함유하는 것으로 나타났다. 총 이온함량과 삼투몰 농도는 염(NaCl) 농도가 증가함에 따라 증가하는 양상을 보였으며, $Na^+$와 같은 무기이온을 직접적인 삼투 조절자로 이용하는 것으로 나타났다. Glycine betaine은 10일째까지는 함량의 변화를 보이지 않았으나 염 처리 후 20일째 200 mM 염(NaCl) 농도까지 현저하게 Glycine betaine 농도가 증가하였으며, 300mM 염(NaCl) 농도에서는 다소 감소되는 양상을 보였다. 근대는 염(NaCl) 스트레스에 대한 세포질성 삼투 조절물질로 Glycine betaine을 축적하는 특성을 나타내었다. 결과적으로, 근대는 식물체 내로의 염(NaCl)의 유입을 배제하는 기작보다는 효율적인 염(NaCl)의 재분배 및 구획화와 무기이온을 삼투조절에 이용하며, Glycine betaine과 같은 세포질성 삼투조절물질을 축적하는 생리적 특성으로 염(NaCl) 환경을 극복하는 것으로 여겨진다.

• 한국식품영양학회지
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• 제11권6호
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• pp.683-688
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• 1998

This study was conducted to develop optimal composition of flour brew in order to economically utilize flour brew inoculated by lactic acid bacteria as a starter(mother sponge) in bread-making. Two flour brews were prepared ; one with flour and water, the other with flour, water and NaCl. Various nutrients were added to both flour brews and Lactobacilli deMan Rogosa and Sharpe (MRS) broth to investigate the effect of them on growth and activities of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture in flour brews to be tested with incubation at 37$^{\circ}C$. The growth of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture was stimulated by addition of NaCl with 0.85% concentratin and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation time. the addition of 3% glucose to flour brew with NaCl was observed to enhance acid productioni by mixed culture. Yeast extract greatly affected growth and activities of mixed culture of lactic acid bacteria in flour brew with NaCl and its optimum level of this additive in flour brew with NaCl was approximately 1.0%. The optimal composition of flour brew for mixed culture of lactic acid bacteria was suggested as follows; flour 100g, water 300g, NaCl 3.46g, glucose 12.48g, yeast extract 3.46g.

• 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.