• Textile Coloration and Finishing
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• v.2 no.1
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• pp.31-36
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• 1990

The electrically conducting cellulose acetate/polypyrrole composite films were synthesized by exposing cellulose acetate film containing oxidizing agent to pyrrole vapour and the formation of polypyrrole is confirmed by IR and electron microscopic studies. The morphologies of polypyrrole in the composites are different depending on the oxidizing agent. Ferric chloride is most effective among several metallic chlorides to synthesize the composites with high electrical conductivity. The conductivity of composite films synthesized with 50 wt.% of ferric chloride reaches upto $10^{-2}S/cm$.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.500-509
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• 2014

To prevent freezing of the road by fallen snow, Calcium chloride($CaCl_2$) as a deicer is used to very often and it can be harmful to roadside trees. This study was conducted to investigate the effects of Calcium chloride($CaCl_2$) as a deicer on growth and physiological traits of Acer triflorum according to different concentration of $CaCl_2$. We measured growth, chlorophyll contents, gas exchangement characteristics, chlorophyll fluorescence and mineral nutrition concentration in plant and soil. The experimental group was composed of four treatments including 0mM(control), 9mM(0.5 %), 18mM(1.0 %), 54mM(3.0 %). Before germinating new shoot, the dissolution of $CaCl_2$ was irrigated twice interval of a week. At 30 days after treatment, all treatments decreased total cholorophyll content, photosynthetic rate, transpiration rate, stomatal conductance and photochemical efficiency($F_v/F_m$) with increasing concentration of $CaCl_2$ and especially, they significantly reduced in 3.0 % treatment. In contrast, chlorophyll a/b ratio increased with an increase of $CaCl_2$ concentration and water use efficiency increased in 1.0 % and 3.0 % treatments. At 50 days after treatment, all treatments were decreased in chl a, chl b, total chlorophyll content, carotenoid content, photosynthetic capacity, photochemical efficiency($F_v/F_m$) and quantum yield of photosystem II(${\Phi}_{PSII}$) compared with control and 3.0 % treatments were withered. $Ca^{2+}$ and $Cl^-$ were accumulated in leaves and soil, which inhibited water absorption and electron transport and it caused the reduction of height growth rate more than 50 %. Although there was a little difference according to time and $CaCl_2$ concentration, all treatments decreased in growth rate and physiological activity slowed down. As time passed, these results got worse. Therefore we need to take a measure earlier in order to minimize damage of trees.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.922-928
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• 2010

There is a little information on the effect of calcium cloride ($CaCl_2$) which is used as deicing salt in Korea on the physiological responses of the street trees. Prunus sargentii is one of the most widespread tree species of street vegetation in Korea. In this study, the effect of $CaCl_2$ on photosynthetic apparatus such as chlorophyll fluorescence image and light response curve of P. sargentii in relation to their leaf and root collar growth responses were investigated. To study the effect of $CaCl_2$ treatment in the early spring, we irrigated twice in rhizosphere of P. sargentii (3-year-old) planted plastic pots with solution of 0.5%, 1.0%, 3.0% $CaCl_2$ concentration before leaf expansion. Results after treatments, total chlorophyll contents and the chlorophyll a/b, photosynthetic rate, quantum yield, dark respiration decreased with increasing $CaCl_2$ concentration. On the contrary, light compensation point increased with increasing $CaCl_2$ concentration. Through the linear regressions of correlation of photosynthetic rate with photosynthetic parameters (quantum yield, dark respiration and light compensation point), we found a significant relationship (p<0.05) between photosynthetic rate and quantum yield and light compensation point except dark respiration. Calcium cloride ($CaCl_2$) induced inhibition of photochemical efficiency ($F_v/F_M$) and non-photochemical quenching (NPQ) were found in treatments of $CaCl_2$, and these reduction rates between control and CaCl2 treatments were drastically showed at 80 days. We suggest that physiological activities are limited from treatment of $CaCl_2$. These reductions of photosynthetic apparatus ability caused eventually the reduction of leaf and diameter at root collar growth.

• Journal of Preventive Medicine and Public Health
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• v.34 no.2
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• pp.127-130
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• 2001

Objective : To verify the separate and combined effects of cadmium and nickel on blood pressure in rats. Methods : Following the daily administration of cadmium chloride$(CdCl_2)$ and nickel chloride$(NiCl_2)$ to rats both individually and in combination with intraperitoneal injection method for one week, systolic blood pressure of the tail was measured at 1 day and 5, 10, 20, 30 days after administration. Each substance was injected into the rats with 0.1 mg/kg bw and 1.0 mg/kg bw concentration. Results : After 0.1 mg/kg bw $CdCl_2$ was injected, a statistically significant difference was found as compared with the control group(only saline) after 1, 5 and 10 days. After 0.1 mg/kg bw $NiCl_2$ was injected, a statistically significant difference was not found compared with the control group. After 0.1 mg/kg bw $CdCl_2$ and 0.1 mg/kg bw $NiCl_2$ were injected simultaneously, a statistically significant difference was found as compared with the control group after 1,5 and 10 days and compared with 0.1 mg/kg bw $CdCl_2$ group after 5 days and as compared with 0.1 mg/kg bw $NiCl_2$ group after 5 and 10 days. After 1.0 mg/kg bw $CdCl_2$ was injected, a statistically significant difference was found as compared with the control group after 1, 5, 10 and 20 days. After 1.0 mg/kg bw $NiCl_2$ was injected, a statistically significant difference was found as compared with the control group after 1 day and 5 days. After 1.0 mg/kg bw $CdCl_2$ and 1.0 mg/kg bw $NiCl_2$ were injected in combination, a statistically significant difference was found after 1, 5, 10, 20 and 30 days as compared with 1.0 mg/kg bw $CdCl_2$ after 10, 20 and 30 days and as compared with 1.0 mg/kg bw $NiCl_2$ after 5, 10, 20 and 30 days. Conclusion : It was found that the effect of $CdCl_2$ on blood pressure was much more than $NiCl_2$ and a high concentration $CdCl_2\;and\;NiCl_2$ in combination delayed the recovery of blood pressure.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.52-58
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• 2005

In Korea, little attention has been paid to microbial perchloroethylene (PCE) and/or trichloroethylene (TCE) dechlorination activity and identification of microorganisms involved in PCE reductive dechlorination at a PCE-contaminated aquifer. We performed microcosm tests using the groundwater samples from 4 different contaminated sites (i.e. Changwon A, Changwon B, Bucheon and Yangsan) to assess PCE reductive dechlorination activity. We also adapted molecular techniques to screen what types of known reductive dechlorinators are present at the PCE-contaminated aquifers. In the Changwon A and Changwon B active microcosms where potential electron donors such as sodium propionate, sodium lactate, sodium butyrate, and sodium fumarate, were added, ethylene, an end-product of complete reductive dechlorination of PCE, was detected after a period of 90 days of incubation. In the Bucheon and Yangsan active microcosms, cis-1,2-dichloroethylene (c-DCE) was accumulated without the production of vinyl chloride (VC) and ethylene. Molecular techniques were used to evaluate the microbial community structures in the Changwon B and Yangsan aquifer. We found two sequence types that were closely related to a known PCE to ethylene dechlorinator, named uncultured bacterium clone DCE47, in the Changwon B site clone library. However, in the Yangsan site clone library, no sequence type was closely related to known PCE dechlorinators reported. It is plausible that microorganisms being capable of completely dechlorinating PCE to ethylene may be present in the Changwon B site aquifer. In this study we find that complete PCE reductive dechlorinators are present at some PCE-contaminated sites in Korea. In an engineering point of view this information makes it feasible to apply a biological reductive dechlorination process for remediating PCE- and/or TCE-contaminated aquifers in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.4
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• pp.61-67
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• 2019

The purpose of this research is to evaluate the salt tolerance of the Miscanthus sinensis and to characterize the content of pigments in the leachate in relation to calcium chloride ($CaCl_2$) deicing salt. Miscanthus sinensis were cultured at five different concentrations of calcium chloride deicing salt, 0, 1, 2, 5, and $10g{\cdot}L^{-1}$ (referred to Cont. C1, C2, C5, and C10) for four months. The salt tolerance and leachate while growing Miscanthus sinensis on soil which was artificially contaminated by calcium chloride deicing salt. Soil chemical properties (pH, E.C., $Ca^{2+}$, $Na^+$, $K^+$, and $Mg^{2+}$) and plant growth parameters (plant height, leaf length, leaf width, number of leaves, shoot fresh weight, root fresh weight, shoot dry weight, an root dry weight) were evaluated. Soil pH decreased, while electrical conductivity significantly decreased ($p{\leq}0.05$) with a higher concentration of deicing salt $0g{\cdot}L^{-1}$ (Cont.). The increase in the concentration of chloride-based exchangeable cations, along with the increase in the deicing salt treatments, were observed in $Ca^{2+}$ > $Na^+$ > $K^+$ > $Mg^{2+}$. Notably the $Ca^{2+}$ exchangeable cations were 83~90% higher than the others. The growth of Miscanthus sinensis significantly increased ($p{\leq}0.05$) with the concentration of deicing salt higher than $1g{\cdot}L^{-1}$ (C1) when compared to 0 g/L (Cont.), except for the $10g{\cdot}L^{-1}$ (C10) treatment. The results determined that the contamination of soil by deicing salt could negatively impact the soil and Miscanthus sinensis was a tolerant species for the deicing salts. Further research will be focused on soil improvement additives and the stable stimulated plant growth of Miscanthus sinensis and a formulation on that basis for the soil-plant continuum.

• 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.

• Cement
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• s.20
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• pp.62-72
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• 1967

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.6
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• pp.65-72
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• 2016

Service life evaluation for RC Structures exposed to chloride attack is very important, however the previous two methods(deterministic and probabilistic method) show a big difference. The paper presents a service life simulation using deterministic and probabilistic method with time-dependent diffusion coefficient. Three different cases are considered for diffusion coefficient, concrete cover depth, and surface chloride content respectively, and then the PDF(probability of durability failure) and the related service life are obtained. Through adopting time-dependent diffusion, the discrepancy between the two methods can be reduced, which yields reasonable service life. When diffusion coefficient increases from $2.5{\times}10^{-12}m^2/sec$ to $7.5{\times}10^{-12}m^2/sec$, the service life decreases to 25.5~35.6% level, and cover depth does from 75 mm to 125 mm, it increases to 267~311% level as well. In the case of surface chloride content from $5.0kg/m^3$ to $15.0kg/m^3$, it changes to 40.9~54.5%. The effect of cover depth is higher than the others by 8~10 times and also implies it is a key parameter to service life extension.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.303-308
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• 2016

To investigate the effect of calcium chloride ($CaCl_2$) using for deicing salts in winter on gas exchange and stomatal responses of 3-year-old Prunus serrulata, we treated twice (1 L) $CaCl_2$ solution (0.5%, 1.0% and 3.0%) in the root zone before leaf unfolding. Stomatal conductance ($g_s$), photosynthetic rate ($P_n$), transpiration rate ($T_r$) and water use efficiency (WUE) in the leaves of P. serrulata were decreased with increasing of $CaCl_2$ concentration. Even though stomatal conductance and photosynthetic rate were reduced by $CaCl_2$, intercellular $CO_2$ concentration ($C_i$) in $CaCl_2$ treatments has similar or higher values compared with control. These results suggest that non-stomatal limitation as well as stomatal limitation induced the reduction of photosynthetic rate together. On the other hands, treatment of $CaCl_2$ before leaf unfolding also affected leaf morphology traits. We proposed that reductions of stomatal length and leaf size and high pore density with increasing salinity is adaptative mechanism to reduce the water loss in plant.