• Corrosion Science and Technology
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• v.17 no.5
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• pp.225-230
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• 2018

The effects of birch sap, a possible natural corrosion inhibitor, on the corrosion behavior of steel in chloride solution were investigated. The corrosion rate was significantly reduced by the addition of 1~5 mL of birch sap to 500 mL of 3wt% NaCl or 3wt% $CaCl_2$ solution. A remarkable increase in the pitting potential in NaCl solution was observed by the addition of birch sap although it was almost constant in $CaCl_2$ solution. The corrosion rate of steel in both NaCl and $CaCl_2$ birch sap solution without addition of water was higher compared to that of aqueous solution without birch sap as the pH of the birch sap was 4.0. The presence of organic compounds like, fructose, galactose, glucose, and palmitic acid in the birch sap are thought to be adsorbed effectively on the metal surface, which provided corrosion protection. However, the inorganic elements including Na, Ca, K, Mg, Mn, S, etc. present in the birch sap exhibited no role in corrosion inhibition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.1
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• pp.11-14
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• 1998

This study was conducted to find out a desirable screening condition for the salinity tolerance in germination of rice. Seeds of 33 rice varieties were tested in NaCl solutions with various concentration levels. The germination percentage had a decreasing tendency with increasing NaCl concentration and inhibition concentration of 50% germination was 320mM. Standard deviation of germination percentage was highest (28.6) under 300mM NaCl. There was a highly significant correlation between the 50% germination concentration and the germination percentage at 20th day after seeding in 300mM NaCl. Also in 300mM NaCl, the germination percentage at 20th day after seeding was significantly correlated with the germination percentage at the 6th day after seeding. The salinity tolerance on the basis of germination percentage at 6th day after seeding in 300mM NaCl, was strong in 'Hyangnambyeo', 'Ilmibyeo', 'Kancheogbyeo', and 'Namwonbyeo', while weak in 'Ansanbyeo', 'Odaebyeo', 'Nonganbyeo', 'Dasanbyeo', and 'Namcheonbyeo'.

• Corrosion Science and Technology
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• v.18 no.6
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• pp.243-252
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• 2019

The pitting corrosion and inhibition studies of AZ31B magnesium alloy were investigated in the alkaline solution (pH12) with chloride and inhibitors. The corrosion behavior of passive film with/without Cl^- in the alkaline electrolyte were conducted by polarization curve and immersion tests in the presence of various additives (inhibitors) to clarify the inhibition efficiency of pitting corrosion at higher potential region. Critical concentration of pitting corrosion for Mg alloy was evaluated with 0.005 M NaCl in 0.01 M NaOH on the anodic polarization behavior. Critical pitting of AZ31B Mg alloy in 0.01 M NaOH is a function of chlorides; E_pit = - 1.36 - 0.2 log [Cl^-]. When the Sodium Benzoate (SB) was only used as an inhibitor, a few metastable pits developed on the Mg surface by an immersion test despite no pitting corrosion on the polarization curve meaning that adsorption of SB on the surface is insufficient protection from pitting corrosion in the presence of chloride. The role of SB and Sodium Dodecylbenzenesulfonate (SDBS) inhibitors for the Mg alloy surface in the presence of chloride was suppressed from pitting corrosion to co-adsorb on the Mg alloy surface with strong formation of passive film preventing pitting corrosion.

• Journal of Ecology and Environment
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• v.39 no.1
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• pp.81-90
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• 2016

This study was to investigate the effect of salt stress on physiological characteristics such as plant growth, photosynthesis, solutes related to osmoregulation of Beta vulgaris. A significant increase of dry weight was observed in 50 mM and 100 mM NaCl. The contents of Chl a, b and carotenoid were lower in NaCl treatments than the control. On 14 day after NaCl treatment, photosynthetic rate (P_N), the transpiration rate (E) and stomatal conductance of CO₂ (g_s) were reduced by NaCl treatment. On 28 day after NaCl treatment, the significant reduction in g_s and E was shown in NaCl 200 mM. However, P_N and water use efficiency (WUE) in all NaCl treatments showed higher value than that of control. Total ion contents (TIC) and osmolality were higher than the control. On 14 day after treatment, the contents of proline (Pro) increased significantly in 200 mM and 300 mM NaCl concentration compared with control, whereas on 28 day in all treatments it was lower than that of the control. The contents of glycine betaine (GB) increased with the increase of NaCl concentration. The contents of Na⁺, Cl^-, GB, osmolality and TIC increased with the increase of NaCl concentrations. These results suggested that under severe NaCl stress conditions, NaCl treatment did not induce photochemical inhibition on fluorescence in the leaves of B. vulgaris, but the reduction of chlorophyll contents was related in a decrease in leaf production. Furthermore, increased GB as well as Na⁺ and Cl^- contents resulted in a increase of osmolality, which can help to overcome NaCl stress.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.350-357
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• 2014

BACKGROUND: Deicers such as calcium chloride ($CaCl_2$) and sodium chloride (NaCl) in Korea have been commonly used to reduce traffic accidents as well as injuries. However there have been adverse effects of deciders such as pollution of water and soil, and reduced productivity of agriculture as well as forest. This study aimed to investigate biological effects of the deicers against wheat, barley, and spinach. METHODS AND RESULTS: The germination of tested crop seeds exposed to chloride-deicers, $CaCl_2$ and NaCl was significantly reduced at over 3% concentration of chloride-deicers compared to the control. In spraying deicers to the seedlings of the crops, there was no symptom such as inhibition of growth rate or leaf elongation. However the germination of tested crop seeds was affected at 2% concentration of deicers when they were exposed continuously to deicers in soils. The growth of the shoot against $CaCl_2$ and NaCl treatments was very similar in wheat and barley whereas the shoot of spinach was the most susceptible. Based on these results, the sensitivity of the crops to the tested deicers was as follows: NaCl > $CaCl_2$ > mixture ($CaCl_2$ + NaCl). The length of shoots and roots of the seedlings grown in 1% treated soil was decreased. The biomass of all the seedlings decreased 1.5 to 4 times at 1%. CONCLUSION: These results indicate that the effects of salt deicers by inputting into soil against growing tested crops are more severe in germination and growth inhibition as well as biomass decrease.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.340-350
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• 1995

This study was conducted to obtain the basic information for the salt stress of Italian Ryegrass. Fourteen cultivars including 7 diploid and 7 tetraploid were subjected to eight levels of NaCl treatments during germination and early seedling stages. Germination percentage decreased remarkably over 300mM of NaCl concentration. The NaCl concentration that inhibited germination of 50% of the viable seeds in the cultivars was 344mM. The decreasing degree of germination percentage was higher in tetraploid type than in diploid type. The varietal difference of germination percentage was shown to be very conspicuous as the NaCl concentration increased. Top dry weight in 166 mM NaCl was decreased by 50% compared with that of control. Inhibition of NaCl appeared to be more in early seedling stage than in germination stage. Top dry weight of cultivars in NaCl stress was not related with germination capacity. Root dry weight in 148mM NaCl decreased by 50% compared with that of control. Root dry weight of cultivars was significantly correlated with top dry weight in NaCl treatment. Top dry weight and root dry weight was higher in diploid type than in tetraploid type at each 8 levels of NaCl concentration. Total chlorophyll content increased with the increase of NaCl concentration and the degree of increase in chlorophyll a was higher than that in chlorophyll b. Chlorophyll a was higher in tetraploid type than in diploid type. But chlorophyll b was higher in diploid type than in tetraploid type. There were significant correlation between chlorophyll a and top dry weight of cultivars over 150mM of NaCl concentration. Free proline content accumulated remarkably in NaCl treatment compared with control and was not difference between diploid type and tetraploid type. Free proline content of cultivars was not related with top dry weight in NaCl treatment.

• Asian Journal of Turfgrass Science
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• v.13 no.2
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• pp.71-78
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• 1999

The influence of increasing livel (0.0, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1.2, 1.6, and 2.0%) fo NaCl on the germination of red fescue (Festuca rubra) 'Sea Breeze', tall fesce(Festucaarundinacea) 'Pixie', creeping red fescue (Festuca rubra ssp. rubra) 'Cindy', annual rye-grass (Lolium multiflorum) 'Permer Ⅱ', perennial ryegrass (Lolium perenne) 'Pennant', fairway wheatgrass(Agropyron cristatum), creeping bentgrass (Agrostis palustris) 'Penncross', and kentucky bluegrass (Poa pratensis) 'Nuglade' was investigated. Red fescue 'Sea Breeze', tall fescue 'Pixie', and creeping red fescue 'Cindy' had greater than 90% seed germination at NaCl concentrations of 0.2% or lower, while showing similar seeding shoot and root lengths and TAA50 values as the control. Creeping red fescue 'Cindy'gave at 0.6% or higher NaCl. Perennial ryegrass 'Pennant' and annual ryegrass 'Permer Ⅱ' showed more than 95% seed germination when NaCl concentrations were 0.4% and 0.8%, respectively. Fairway wheatgrass, creeping bentgrass 'Penncross' and Kentucky bluegrass 'Nugade' had showing similar germination percent, shoot and root lengths and T50 values as the control at NaCl concentrations of 0.1% or lower. In general, germination percent and the lengthes of seedling roots and shoots of all species tested decreased as NaCl concentrations iscreased. The T50 values became greater as NaCl concentration increased. Seed fermination in red fescue 'Sea Breeze', tall fescue 'Pixie',perennial ryegrass 'Pennant', and annual ryegrass 'Permer Ⅱ' was compoetely inhibited at 2.0% NaCl. Creeping red fescue 'Cindy' and fairway wheatgrass gardly germinated at 1.6% MaCl. Creeping bentgrass 'Penncross' and Dentucky bluegrass 'Nuglade' showed a complete inhibition of germination at 1.2% and 0.6% NaCl, respectively.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.155-160
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• 2017

The dye decolorization rate in a cell-free culture broth of the white-rot fungus Trametes versicolor CBR43 was studied, including the effects of inhibitors of NaCl, Zn(II), and Cd(II) on dye decolorization activity. The maximum rates of dye decolorization in cell-free culture broth were 1,410, 44.7, 41.2, and $0.19{\mu}mol{\cdot}l^{-1}{\cdot}min^{-1}$ for Acid Blue 62, Acid Black 175, Reactive Blue 4, and Acid Red 114, respectively. The inhibition effects of NaCl, Zn(II), and Cd(II) on dye decolorization were quantitatively compared using the half maximal inhibition concentration ($IC_{50}$), which indicates the concentration of an inhibitor required for 50% inhibition. Based on $IC_{50}$ values, dye decolorization in the cell-free culture broth of CBR43 was most potently inhibited by Cd(II), whereas the inhibitory effect of NaCl was relatively low. The dye decolorization rates and $IC_{50}$ data can be used in the design and development of a dye-wastewater treatment process using T. versicolor CBR43 and its operating factors.

• Journal of Life Science
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• v.18 no.2
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• pp.154-161
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• 2008

The physiological and photochemical responses of rice seedling to NaCl stress were investigated through measuring leaf relative water content (RWC), root water uptake and chlorophyll fluorescence. When plants were exposed to increased salinity stress, the visual symptoms of injury were significant at ${\geq}$500 mM NaCl concentration for 4 and 5 day stress periods. The differences in Fv/Fm between control treatment and plants treated with 500 mM and 1,000 mM NaCl were evident after 5 day and 4 day, respectively, whereas in root water uptake its effect was observed at 500 mM and 1,000 mM NaCl at 2 day of salt-stressed periods. Leaf RWC in salt-stressed plants decreased gradually with increasing salinity in exogenous solution and duration of salt stress, and these decrease showed leaf RWC of 58-68% atduration over 2 day stress of 1,000 mM NaCl treatment and 88% at 1 day stress. NaCl stress led to a significant inhibition of the light-induced greening in etiolated rice plants, especially in 4 and 5 day salt-stressed plants, which linearly decreased with NaCl concentration ($R^2$=0.812 and 0.918, respectively). The effects of NaCl stress in rice seedlings indicate that water uptake in root is more sensitive to increasing NaCl concentration and stress duration than Fv /Fm in leaves compared with the same NaCl concentration.

• Journal of Life Science
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• v.16 no.4
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• pp.605-611
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• 2006

To investigate the possible use of probiont in fish farming industry, a bacterium with inhibitory effect against Vibrio anguillarum was isolated from gastrointestinal tract of the marine fish of yellow tail. It was identified to be Bacillus amyloliquefaciens H41 based on biochemical and physiological characterization. The optimal growth conditions of the isolated strain were 1% peptone, 1.5% yeast extract, 1% sucrose, 0.5% NaCl, 0.05% $MgSO_4{\cdot}7H_20$, pH 7.0-8.0, and 20 hr of incubation between $28-35^{\circ}C$ under aeration. The culture supernatant of the isolated strain showed inhibition activity against V. anguillarum. Inhibition activity was cleared by forming a clear zone by a paper-disk method. The maximal production of growth inhibition factor was induced by cultivation under 1% peptone, 1.5% yeast extract, 1% sucrose, 1% NaCl, 0.05% $MgSO_4{\cdot}7H_20$, pH 7.5 and at $35^{\circ}C$. The highest growth inhibition factor production was observed after 16-24 hr cultivation under aeration. The culture supernatant of the isolated strain showed inhibition activity whereas no inhibition activity was shown from the standard B. amyloliquefaciens KCTC 1724 strain. The growth inhibition affected only against V. anguillarum among other pathogenic Vibrios tested here.