• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.517-526
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• 2023

The harvest time of the late-ripening 'Fuji' apple (Malus × domestica) is variable, depending on the coloration of the fruit skin. Ethephon, a plant growth regulator, promotes the ethylene production and induces physiological responses associated with fruit maturation in climacteric fruit crops, such as apples. This study aimed to investigate the effect of ethephon treatment on fruit characteristics after fruit enlargement, with the objective of proposing an economical and stable harvest control method for 'Fuji'/M.26 apples. Fruit characteristics were assessed at 10-days intervals following the application of 100 mg/L ethephon and mixture of 100 mg/L ethephon and 0.5% CaCl₂ at 145 days after full bloom (DAFB). Starch contents of ethephon-treated (ET) and ethephon with CaCl₂-treated (EC) apples began to decrease from 155 DAFB, and the starch contents of ET and EC at 10 days before harvest were similar to those of control at harvest time. Red coloration of fruit skin in EC was lower compared to ET but higher than control. The average fruit firmness was low in ET, while the control and EC exhibited similar levels of firmness. Fruit sugar acid ratios did not show significant differences between treatments. However, the titratable acidity of EC was significantly lower than that of the control at 10 days before harvest. Moreover, fruit sugar acid ratio of ET and EC at 10 days before harvest in 2021 was similar to their sugar acid ratio at harvest time. Therefore, it was thought that fruit maturation and skin coloration could be accelerated by 10 days from the harvest time through the combined treatment of 100 mg/L ethephon and 0.5% CaCl₂ at the end of fruit enlargement in 'Fuji'/M.26.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.388-394
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• 2013

Growth, inorganic solutes and glycine betaine accumulation in spinach beet (Beta vulgaris var. cicla L.) were studied under different salt conditions. Plants of fortythree days old were assessed by growing for a further 10 and 20 days at four NaCl concentrations (0, 100, 200, 300 & 400 mM). The dry weight of leaves was maximal in plants which were grown at 100 to 200 mM NaCl treatments and after 10d it was decreased slightly at salt treatments of more than 300 mM NaCl. Under the salt conditions, leaves of B. vulgaris contained high inorganic ions to maintain low water potential, but low water soluble carbohydrate contents. Total ionic content and osmolality increased with increasing salt concentration. Salt stress led to a preferential accumulation of glycine betaine in leaves of B. vulgaris, especially for the 200 mM NaCl treatment. These findings suggest that a high degree of NaCl tolerance of B. vulgaris resulted from the accumulation of glycine betaine, which is known to have osmoprotectant properties in the cytoplasm.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.333-338
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• 1987

In order to establish the biological treatment system which can be used for treatment of waste aster from acetaldehyde plant, it was investigated optimum nutrient requirements and growth conditions by mixed culture of Micrococcus roseus AW-6, Micrococcus luteus AW-22, Microbacterium lacticum AW-38 and Microbacterium laevaniformans AW-41 as well as the effect of coagulants and neutralization reagents. Also, it was carried out the continuous culture as well as batch culture to treat the waste water by mixed culture of these strains. The COD removal rate was reached to maximum state for 96hrs culture at pH7.0 and $30^{\circ}C$ NaOH as the neutralization reagents was the most effective, but the coagulants had no effect on the COD remonal rate and the optimum dilution times for treatment were 10 fold. The COD removal rate was also increased by supplimenting 200 ppm $NH_{2}NO_{3}$, 50 ppm $KH_{2}PO_{4}$, 15 ppm $CaCl_{2}$ and 1 ppm $MgSO_{4} \cdot 7H_{2}O $ as additional nutrients. The removal rate coefficient $K_{1}$ on the batch culture was $4.5\times 10^{-6}$, and the detention time for BOD removal rate of 85% was approximately 45hrs. The COD of waste water was reduced to 15% of its initial value by the continuous culture. The COD and BOD of the effluents were to be about 60 ppm and 40 ppm, respectively, and final pH was 7.0.

• Nuclear Engineering and Technology
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• v.5 no.4
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• pp.310-320
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• 1973

The sorption and fixation of cesium in dilute solutions by vermiculite saturated with Na or K were studied in order to investigate any possibibty of its use in radioactive effluent treatment. The cesium sorbed by vermiculite with the increase in pH is attributed to the increase of sorption surface as a result of the dispersion. The increased cesium sorption by Na-vermiculite is due to the different sorption rates by the different exchange sites : external surface and internal surface. It is shown that the larger amount of sorbed cesium was extracted by KCI rather than with any other extractants. It is suggested that the fixation of cesium by vermiculite occurs at the crystal edge where Cs may replace K. Domestic vermiculite is a valuable material for use in the cesium sorption and fixation, and might be useful as a good packing material outside the tank of highly radioactive liquid waste. And from these results one could suggest that the artificial alteration of the biotite to vermiculite might be occurring by treating with NaCl.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.5
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• pp.67-76
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• 2013

In this study, the inhibitive effect of electrochemical treatment subjected to fresh and hardened concrete and literature reviews in terms of the treatment were performed. In hardened concrete, chloride ions are mixed during casting to destroy the passivity of steel, and then the current was provided for 2 weeks with 250, 500 and $750mA/m^2$. After completion of electrochemical treatment, the extraction of chloride ions was quantified and repassivation of steel was observed. Simultaneously, the equated levels of current density for 2 weeks were applied to fresh concrete. Steel-concrete interface in concrete was observed by BSE image analysis and the concrete properties in terms of the diffusivity of chloride ions and the resistance of steel corrosion was measured. As the result, electrochemical treatment is very effectiveness to rehabilitate the passive film on the steel surface and 63-73% of chloride ions in concrete were extracted by the treatment. As the treatment was applied to fresh concrete, the resistance of steel corrosion was improved due to the densification of $Ca(OH)_2$ layers in the vicinity of steel. However, an increase in the current density resulted in an increase in surface chloride content of concrete.

• KSBB Journal
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• v.8 no.2
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• pp.150-155
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• 1993

This study describes biodegradation of dyes which are used in textile industries. Dyes released into the environment from industrial waste water are considered to be a serious pollution problem because of the wide spread into environment with a variety of colors. The microorganisms used in this experiment were Pseudomonas species, which had been screened from aeration tank of waste water treatment. It was found that optimum concentrations for culture media were 14g of glucose, 6g of peptone, 160 mg of Na2HPO4, 200mg of KCl, 140mg of MgSO4,.7H2O,1.0g of KH2PO4, 400mg of NaCl, 200mg of CaCl2 and dye 10ppm per litre of distilled water. The high efficiency of dye degradation was obtained at pH 7-8 and $30-35^{\circ}C$. Strains screened are excellent for removal of azo and reactive dyes, which are relatively stable and difficult to degrade. Dyes of 10ppm such as mono-azo (Lot No. 180), di-azo (Lot No. 138) and reactive red(Lot No. 2) were mostly decolorlzed within 2 days and di-azo (Lot No. 151) and reactive red(Lot No. 34, No. 00166) were decolorized within 5 days in the controlled fermenter. In the case of reactive dyes, oxygen supplies showed lower biodegradability compared to anaerobic culture.

• Journal of Conservation Science
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• v.29 no.4
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• pp.297-309
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• 2013

Iron objects become corroded at fast speed from the moment when they are excavated, so it is needed to control corrosion through processes of conservation treatment. However, re-corrosion mostly takes place in excavate iron objects, although they have already gone through the process of conservation treatment, and it is more difficult to carry out the second conservation treatment of re-corroded excavated iron objects than the first conservation treatment, and it requires a longer period of time to treat them as well. In this study, aims to discover factors of re-corrosion by scientifically analyzing corrosion products generated during the process of storage after the process of conservation treatment. The finished on conservation treatment of the iron artifacts, which were unearthed from three ancient site in Gyeongju by using the same conservation method between 2002 and 2009, re-corrosion condition observed on the packaging-iron artifacts. Focused on 9 target forged iron artifacts among them, this study analyzed the physical changes by mass measurement, naked-eye and microscopic observations and the chemical changes by SEM-EDS, XRD, IC and ICP analysis. The results show that the yellowish brown corrosion products formed on the facing surface of part dropped from the artifacts had different associated forms but acicular shape. In addition, the acicular shape became clearer as the color changed from red to yellowish brown. According to the process when the conservation treatment was completed, the mass of the artifacts increased in proportion to the corrosion products and the chloride ion ($Cl^-$) concentration had a tendency to increase relatively. ${\beta}$-FeOOH (akaganeite) was confirmed in the XRD analysis for the corrosion products of all the collected samples. As a result of ICP analysis, $Na^+$ and $Ca^{2+}$ components were confirmed.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.460-465
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• 1990

Regeneration of protoplast was effective by preincubating spore suspension containing 30$\mu g$/ml of 2-DG for 4 hours, and CBE medium containing casamino acid, bovine serum albumin, ergosterol and myoinositol was found to be more efficient than any other regeneration medium tested in this experiment. The regeneration frequency was about 30%. Optimal conditions for conidial protoplast fusion were obtained by treatment of protoplasts with 10 mM $CaCl_2$ and 30% polyethylene glycol 4000 (pH 7.5) as fusogenic agent at $37^{\circ}C$ for 10 minutes. The fusion frequency was $8.2\times 10^{-4}$. The higher productivity of enzyme of fusant FWN-56 was achived: 2.3-fold for CMCase, 1.5-fold for avicelase, 1.8-fold for $\beta$-glucosidase and 2.5-fold for xylanase compared to that obtained in two parental strains. The genetic stability of fusant after maintenance on minimal medium for more than 4 weeks was high because segregant rate was below 1%. The conidial DNA content of fusant was 1.4-1.6 times higher than that of the parental strains, The nucleus size of fusants were also higher than that of each parental strains.

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.213-221
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• 2007

The treatment of radish cotyledons with a nitric oxide (NO)-releasing substance, sodium nitroprusside (SNP) resulted in an increased adventitious root development in a dose-dependent manner. However, this NO-mediated enhancement effect was reversed when either 0.5 mM EGTA (an extracellular $Ca^{2+}$ chelator) or 0.1 mM $LaCl_3$ (a calcium channel blocker) was applied with $50\;{\mu}M$ SNP. Our results also showed that guaiacol peroxidase (GPX) and syringaldazine peroxidase (SPX) activities, which are known to play a key role in rooting, were more largely increased during adventitious root induction in the cotyledons treated with SNP. However, the treatment of cotyledons with SNP plus $LaCl_3$ inhibited the SNP-induced increases in the activities of both GPX and SPX. Trifluoperazine (TFP), an antagonist of calmodulin (a specific calcium-binding protein), also delayed adventitious root formation and significantly reduced the root length and number of the SNP-treated cotyledons as well as the deactivation of GPX and SPX enzymes. In conclusion, our results suggest that calcium is involved in the NO response leading to induction of adventitious root through a regulation of GPX and SPX.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.964-969
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• 1995

For the effective utilization of cellulosic biomass, conidial protoplast fusion between Aspergillus niger MAN-831(${\beta}-glucosidase$) and A. wentii MAW-538(CMCase and avicelase), which produced potently cellulolytic enzymes was carried out. Optimal conditions for formation and regeneration of protoplast were conidiospore age-5 dyuas. $2-DG-30\mu\textrm{g}/ml$, preincubation time-4 hours, osmotic stabilizer-0.7M KCl, novozyme(7mg/ml)＋driselase(2.5mg/ml) and reaction time of enzyme-5 hours. Optimal conditions for protoplast fusion were obtained by treatment of protoplasts with 15mM CaCl2 and 25% polyethylene glycol 4000(pH 6~7) as fusogenic agent at $36^{\circ}C$ for 25~30 minutes. The frequency was then $7.94{\times}10^{-4}$. CMCase, avicelase and ${\beta}-glucosidase$ activity of fusant F-208 strain was 1.5, 1.3, 1.2 times higher than those of parental strains, respectively.