• Korean Chemical Engineering Research
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• v.59 no.3
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• pp.399-409
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• 2021

In order to utilize dolomite as a calcium/magnesium compound material, it was prepared highly reactive calcined dolomite(CaO·MgO) using a microwave kiln (950 ℃, 60 min). The experiment was performed according to the standard of the hydration test (ASTM C 110) and hydration reactivity was analyzed as medium reactivity (max 74.1 ℃, 5 min). Experiments were performed with calcined dolomite and salt (MgCl₂·6H₂O) (a) 1:1, (b) 1:1.5, and (c) 1:2 wt% based on the hydration reaction of calcined dolomite. The result of X-ray diffraction analysis confirmed that MgO of calcined dolomite increased to Mg(OH)₂ as the salt addition ratio increased. After the separating reaction, calcium was stirred at 80 ℃, 24 hr that produced CaCl₂ of white crystal. XRD results, it was confirmed calcium chloride hydrate (CaCl₂·(H₂O)x) and CaO of calcined dolomite and salt additional reaction was separated into CaCl₂. And it was synthesized with Ca(OH)₂ 99 wt% by NaOH adding reaction to the CaCl₂ solution, and the synthesized Ca(OH)₂ was manufactured CaO through the heat treatment process. In order to prepare calcium carbonate, CaCO₃ was synthesized by adding Na₂CO₃ to CaCl₂ solution, and the shape was analyzed in cubic form with a purity of 99 wt%.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.66-70
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• 1990

Correlations have been developed for estimating the viscosities of ternary mixtures of sucrose-sodium chloride-water over a temperature range of $10-40^{\circ}C$ and a concentration range of 1.0064-5.7037 molality sodium chloride and 0.3436-2.5966 molality sucrose. The viscosity data of sodium chloride and sucrose solutions have been fitted very well utilizing proposed polynomial equation, respectively and the temperature dependence analysis for sodium chloride and sucrose solutions showed that 1/T dependence is accurate. The experimental viscosity data for surose-sodium chloride-water mixtures were fitted to a five parameter polynomial with a goodness of fit approximating experimental error and it seems that there is no significant Interaction between sodium chloride and surose solutions.

• Environmental Analysis Health and Toxicology
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• v.20 no.1
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• pp.75-85
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• 2005

This study was aimed to know the effect of cadmium chloride (CdCl₂) on glucose transport in L6 myotube and its action mechanism. CdCl₂ increased the 2-deoxy- (l-3H)-D-glucose (2-DOG) uptake 1.9 and 2.4 fold at 10 and 25 μM respectively. To investigate the stimulating-mechanism of glucose transport induced by CdCl₂, the wortmannin and PD98059 were used as PI3K (phosphatidylinositol 3-kinase) inhibitor and MAPK inhibitor respectively, which did not affect 2-DOG uptake. This fact suggests that CdCl₂ induced 2-DOG uptake may not be concerned to the insulin signalling pathway. Whereas nifedipine, a calcium channel blocker, and trifluoperazine, a calmodulin inhibitor, were found to inhibit the 2-DOG uptake stimulted by CdCl₂. In addition, we also measured the ROS (reactive oxygen species) production and GSH level in L6 myotube to investigate the correlation between the glucose uptake and ROS. CdCl₂(25 μM) increased ROS generation approximately 1.5 fold and changed the cellular GSH level, but GSSG/GSH ratio remained unchanged. CdCl₂ stimulated 2-DOG uptake and ROS generation were inhibited by N-acetylcystein. And BSO pretreatment, a potent inhibitor of γ-GCS, resulted in the dramatic decrease of 2-DOG uptake and also the increase of the sensitivity to cadmium cytotoxicity. The obtained results suggest that CdCl₂-stimulated glucose uptake might be based on the activation of HMP shunt as an antioxidant defense mechanism of the cells.

• Journal of agriculture & life science
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• v.45 no.5
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• pp.81-89
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• 2011

This study was carried out to investigate changes in physicochemical and sensory properties of cooked sausages replaced sodium chloride (NaCl) to potassium chloride (KCl) or magnesium chloride ($MgCl_2$) during storage for 30 days under $4^{\circ}C$. All sausages were prepared with different combination of salts as follow; CTL (1.5% NaCl), KCL (0.9% NaCl+0.6% KCl), MCL (0.9% NaCl+0.6% $MgCl_2$), KML (0.9% NaCl+0.3% KCl+0.3% $MgCl_2$) and PST (1.5% PanSalt). Among sausages moisture content in KML was the highest (p<0.05). Lightness and redness in CTL were lower than those of other treatments, but MCL and KML containing $MgCl_2$ showed higher CIE $L^*$ and $a^*$ values than CTL. The pH in CTL was the highest during storage, however, no significant difference was determined between two treatments, MCL and KML (p>0.05). Crude fat content and water holding capacity (WHC), hardness and cohesiveness of MCL sausages were higher than those of CTL. In sensory characteristics of cooked sausages, saltness in MCL was the lowest during 10 and 20 days of storage (p<0.05). Yellowness in PST was lower than other treatmeants. Gumminess and chewiness of texture property of sausages from MCL and KML were higher than CTL. The results indicate that the replacement of NaCl by KCl improved texture, but meat color was not improved as expected. In contrast, the replacement of NaCl by $MgCl_2$ enhanced color, texture and WHC, whereas partial replacement of NaCl by $MgCl_2$ must reduce bitter taste as compared to sausages manufactured with a NaCl only. Therefore, $MgCl_2$ may be a salt replacing NaCl in cooked pork sausages.

• Journal of Environmental Health Sciences
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• v.25 no.3
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• pp.77-82
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• 1999

This study was carried to investigate the characteristics of chloramination as a disinfection in drinking water distribution system. The raw water comes from midstream of Han river. In the range of pH 6~8, preformed chloramine of $Cl_2/NH_3-N$ ratio 5:1 had the HPC inactivation of more than 99% with lower pH and shorter contact time and available chloramine residual was decreased a little. In the chloramines of $Cl_2/NH_3-N$ ratio 3:1~5:1, the higher $Cl_2/NH_3-N$ ratio, the much inactivation of HPC was increased, but as contact time was longer, HPC inactivation of $Cl_2/NH_3-N$ ratio 3:1~5:1 were equaled. Bactericidal activity of three chlorine and postammoniation was influenced by free available chlorine completely and that of preammoniation was as follows : free chlorine ${\fallingdotseq}$ postammoniation>preammoniation>preformed chloramine.

• Journal of the Korean Magnetics Society
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• v.9 no.1
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• pp.17-22
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• 1999

Hexagonal M-type barium ferrite $BaFe_{12}O_{19}$ was prepared by a direct solid state reaction between $BaCO_3$ and ${\Alpha}-Fe_2O_3$ powders at temperatures ranging from 800 to 1000 $^{\circ}C$ in a nitrogen or air environment. The effects of NaCl on phase transformation of mixture of $BaCO_3$ and ${\Alpha}-Fe_2O_3$ to $BaFe_{12}O_{19}$ were studied using X-ray diffraction and M$\"{o}$ssbauer spectroscopy. Regardless of the environment for heat treatment or the added NaCl, two phases, BaFe and ${\Alpha}-Fe_2O_3$, coexist for samples heat treated at 800 $^{\circ}C$, but a single phase was observed from samples heat treated at 100$0^{\circ}C$ in both air and nitrogen environments. It was found that the addition of NaCl reduced the amount of $a-Fe_2O_3$ phase.hase.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1303-1309
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• 2012

A novel ligand N,N'-(2,6-pyridinedicarbonyl)bis[N-(carboxymethyl)] (L1) was designed and synthesized. Four co-luminescence groups of Sm-La-pyridyl carboxylic acids systems were researched, which are $K_4Sm_{(1-x)}-La_x(L_1)Cl_3{\cdot}y_1H_2O$, $K_4Sm_{(1-x)}La_x(L_2)Cl_3{\cdot}y_2H_2O$, $K_6Sm_{2(1-x)}La_{2x}(L_3)Cl_6{\cdot}y_3H_2O$, $K_4Sm_{(1-x)}La_x(L_4)Cl_3{\cdot}y_4H_2O$. The results indicated the addition of La(III) could sensitize the luminescence of Sm(III) obviously in a certain range, enhancing emission intensity of Sm-pyridyl carboxylic acids relative to the undoped ones. The optimal mole percentages of La(III) in the mixed ions for $L_1$, $L_2$, $L_3$, $L_4$ were confirmed to be 0.6, 0.5, 0.3, 0.6, respectively. The mechanism of the fluorescence enhancement effect was discussed in detail. Furthermore, the binding interaction of $K_4Sm_{0.4}La_{0.6}(L_4)Cl_3{\cdot}5H_2O$ with bovine serum albumin (BSA) have been investigated due to its potential biological activity. The binding site number n was equal to 1.0 and binding constant $K_a$ was about $2.5{\times}10^5\;L{\cdot}mol^{-1}$.

• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.166-172
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• 2003

Calcium lactate (CL) prepared from powdered black snail (PBS) or its ashed powder (ABS), was investigated for ideal manufacturing conditions to optimize color, solubility and sensory quality. Based on the amount of PBS and 100 mL lactic acid (LA), the yields of PBS-CL were 300% and 15 g in 10% LA and 260% and 20 g in 20% LA. Yields of ABS-CL based on the amount ABS and 100 mL LA were 400% and 60 g in 10% LA and 329% and 66 g in 20% LA. Both of the yields were decreased with an increase of the LA concentration on the basis of PBS and ABS amounts, but proportionally increased with the increment in the LA concentration on the basis of LA volume. Optimal preparation times of the dehydrated PBS-CL and ABS-CL were, respectively, 4 hr and 5 hr at 10$0^{\circ}C$, 3 hr and 4 hr at 12$0^{\circ}C$, and 1 hr and 2 hr at 15$0^{\circ}C$, which showed shorter time in preparing the dehydrated ABS-CL. PBS-CL and ABS-CL were confirmed to be Ca($CH_3$CHOH$CO_2$)$_2$ by the analysis results of IR and $^1$H-NMR. Calcium contents of the anhydrous PBS-CL and ABS-CL were individually 15.4% (w/w) and 17.3% (w/w) representing 84.2% and 94.5% or each theoretical value. Colors or PBS-CL and ABS-CL were light yellow and light-greenish white each. Solubilities of PBS- CL and ABS-CL in distilled water at pH 3~8 were 5.43 and 6.11 g/100 mL, respectively, which demonstrated higher mean solubilities rather than the 4.74 g/100 mL of standard CL. Solubilities of PBS-CL (3.14~5.03 g/100 mL) and ABS-CL (4.69~6.05 g/100 mL) against soup soy sauce, 3% brine, Soju (Korean distilled liquor), thick soy sauce, grape juice and orange juice were higher than those of standard CL (2.94~5.84 g/100 mL). ABS-CL was believed to have a wide use range due to its low sourness while different applications of PBS-CL in food are expected due to its mild astringent taste and strong savory taste despite its strong bitter taste as estimated by sensory evaluation.

• East Asian mathematical journal
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• v.32 no.1
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• pp.43-46
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• 2016

The Clausen function $Cl_2$(x) arises in several applications. A large number of indefinite integrals of logarithmic or trigonometric functions can be expressed in closed form in terms of $Cl_2$(x). Very recently, Choi and Srivatava [3] and Choi [1] investigated certain integral formulas associated with $Cl_2$(x). In this sequel, we present an interesting new definite integral formula for the Clausen function $Cl_2$(x) by using a known relationship between the Clausen function $Cl_2$(x) and the generalized Zeta function ${\zeta}$(s, a). Also an interesting integral representation for the Catalan constant G is considered as one of two special cases of our main result.

• Journal of Plant Biology
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• v.36 no.1
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• pp.113-120
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• 1993

Effects of various NaCl concentrations on salt-tolerant callus of tobacco were investigated. Selection of NaCl-tolerant (S) callus was conducted by subculturing Nicotiana tabacum cv. BY 4 callus in 200 mM NaCl-containing MS medium for more than 18 months. In spite of the long subculture period, characteristics of salt tolerance were maintained very stably. Significant differences were found in ion contents of each callus which was subcultured with treatment of various NaCl concentrations: Na+ and Cl- became higher but Mg2+, Ca2+ and K+ became lower with the increasing external salt contents. Therefore, the ratios of Na+/Ca2+ and Na+/K+ also increased resulting close to those of halophytic property. The contents of chlorophylls and carotenoids in S callus were estimated to 3.1 and 2.9 times more, respectively. than those of non-selected (NS) callus (control). The higher content of external NaCl tended to increase the amount of water soluble proteins and to decrease the amounts of the total sugars, reducing sugars and free amino acids. The activity of peroxidase was increased with higher contents of external NaCl in S callus, but it was maintained at a higher level than S callus at lower NaCl, followed by a subsequent decrease above 80 mM NaCl in NS callus. These results suggest that S callus may have a biological system converting energy source to efficient growth leading to reduction of the growth inhibition under stress environment.