• Journal of the Korean Chemical Society
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• v.9 no.4
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• pp.179-184
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• 1965

Korean acid clays and Japanese acid clay were 1 N KCl solution and then their acidities were determined by measuring pH of the filtrates produced. And on examining the effect of neutral salt solution, such as KCl, NaCl, $BaCl_2,\;Pb(NO_3)_2\;and\;CuSO_4$, on the acidity, it was found that the effect decreased in order mentioned above and this situation proved to be in accord with Lyotrope series, i.e., the order of $K^+>Na^+>Ba^{++}>Pb^{++}>Cu^{++}.$ And after adsorbing cation, $Al_2O_3\;and\;Fe_2O_3$ which dissolved out of acid clay were measured, with the result that the amounts dissolved out were nearly proportional to acidity. This result accords with Kobayashi and Yamamoto's theory that the cause for acidity of clays is due to the fact that HCl which is formed initially by exchange of cation reacts with solid clay, and then chlorides dissolved out bring about hydrolysis, then resulting in the second formation of HCl. On measuring the rate which acid clay adsorbed dye in aqueous solution of basic and acid dyes, it was found that acid dye had no relation to acidity, and though it was not adsorbed by acid clay, the adsorption rate of basic dye was proportional to acidity. After adsorbing basic dye, pH was proportional to both acidity of solid acid and its adsorption rate of dye. Hence, it was concluded that the adsorption of basic dye was in accord with adsorption mechanism of neutral salt. This study led to find the acidic cause of solid acid and its adsorption mechanism of dye in aqueous solution.

• The Korea Journal of Herbology
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• v.35 no.3
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• pp.17-24
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• 2020

Objectives : The objective of this study was to evaluate the gastric protective effect of Curcuma Longae Rhizoma (CLR) in 150 mM HCl/60% ethanol induced gastric ulcer (GU) in mice. Methods : Forty ICR mice were divided into five groups (n=8/Group): Nor group; Normal, Veh group; GU control, SC group; GU + sucralfate 10 mg/kg, CL; GU + CLR 30% ethanol extract 100 mg/kg, CH group; GU + CLR 30% ethanol extract 200 mg/kg. Then, mice were orally administered with 150 mM HCl/60% ethanol and caused GU. After 1 hr, mice were sacrificed, and blood and stomach tissue were collected. Results : CLR showed significance scavenging effects in 1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) radical scavenging activities (DPPH IC₅₀; 78.18 ± 0.60 ㎍/㎖, ABTS IC₅₀; 55.91 ± 1.86 ㎍/㎖). CLR significance reduce inflammatory-related factors such as cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin-6 (IL-6) via nuclear factor kappa B (NF-κB) inactivation. In addition, the activation of nuclear factor erythroid2-related factor 2 (Nrf2) significantly led to up-regulation of anti-oxidant enzymes including factors heme oxygenase-1 (HO-1), super oxide dismutase (SOD), and glutathione peroxidase-1/2 (GPx-1/2). Conclusions : Our discovery provides that CLR possesses anti-oxidant and anti-inflammatory effects. Hence, CLR may ameliorate the development of gastric ulcer though the inhibition of NF-κB inflammatory pathway and the elevation of Nrf2 anti-oxidant pathway.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04a
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• pp.84-88
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• 1999

In chlorine dioxide delignigication or bleaching, chlorate is mainly formed by the reaction between chlorite and hypochlorous acid, thus scavengers of chlorine or hypochlorous acid can be used to reduce the formation of chlorate which is unfavorable to environment. In this study, additives such as sulfamic acid, DMSO, hydrogen peroxide, or sodium chlorite was added to chlorine solution or pure $ClO_2$ solution to check their reactivity with $Cl_2$ and $ClO_2$. These additives were also added directly into general $ClO_2$ solution which contained certain amount of chlorine, then the additive-treated $ClO_2$ solution were used in bleaching stages. The aim of this procedure was to remove the original amount of chlorine that was thought to be possibly the main reason for the formation of chlorate and AOX. The additives were found to be able to eliminate chlorine very fast and selectively, but $H_2$ $O_2$ should be used under pH4, otherwise it also reacts with $ClO_2$. After the additives reacted With $Cl_2$, DMSO turned into an inactive product $(CH_3)_2SO_2$, While Sulfamic acid turned into $HClSO_3H$ that still remained active in oxidation, and $NaClO_2$ produced $ClO_2$. The addition of $HNaClO_2$ showed significant improvement in delignification but the deeper delignification led to higher formation of chlorate. When the additive-treated chlorine dioxide solutions were used in bleaching, both sulfamic acid, DMSO, and hydrogen peroxide showed no significant changes of DE brightness and Kappa number. The formation of chlorate was reduced by addition of sulfamic acid, DMSO and hydrogen peroxide.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.327-334
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• 2016

In order to compare phosphorus (P) behavior of livestock manure compost (LMC) and chemical fertilizer (CF) applied to the sea-reclaimed land soils, incubation experiments were conducted for five weeks. Four soils differing textural classes, sandy loam and clay loam, and electric conductivity (EC) value, high and low, were applied with CF and LMC. LMC was applied at the level of 0, 1, 2, and 3% on the soil weight basis and CF was applied at the same levels of P as LMC. The results showed that increase of P application rate of CF and LMC led to linearly increase available $P_2O_5$ and $0.01M\;CaCl_2$ extractable P contents regardless of soil texture and EC. However, 0.01M $CaCl_2$ extractable P from soil applied with CF was significantly higher than with LMC. Correlation analysis between $0.01M-CaCl_2$ extractable P and fractionated P by different extraction methods showed that $0.01M-CaCl_2$ extractable P positively correlated with KCl-P (soluble and exchangeable P) and HCl-P (Ca and Mg bound P). However, NaOH-P (Fe and Al bound P and organic P) and residual P was adverse. The amount of NaOH-P significantly influenced to the amount of 0.01M $CaCl_2$ extractable P of CF and LMC in the soils. The application of LMC at sandy loam soil could be carried out in the consideration of nutrient leaching and crop uptake.

• Resources Recycling
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• v.25 no.2
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• pp.3-9
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• 2016

Separation of Zr(IV) and Hf(IV) from sulfuric acid solutions was investigated by extraction with several acidic extractants such as Versatic acid, LIX 63, and Cyanex 301. From strong sulfuric acid solutions, the separation of Zr(IV) and Hf(IV) by Versatic acid and LIX 63 was not possible, while selective extraction of Hf(IV) over Zr(IV) was obtained with Cyanex 301. However, the extraction percentage of the two metals was much lower compared to that by D2EHPA. Mixing of TBP with Cyanex 301 and D2EHPA led to negative effect on the extraction and separation of the two metal ions. The difference in the extraction reaction and separation selectivity between HCl, $HNO_3$ and $H_2SO_4$ media with each extractant was discussed.

• Resources Recycling
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• v.30 no.6
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• pp.36-42
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• 2021

Spent lithium-ion batteries are treated by reduction-smelting at high temperatures to recover valuable metals. Solvent extraction and precipitation of the HCl leaching solution of reduction-smelted metallic alloys resulted in a filtrate containing Ni(II) and a small amount of Si(IV). Adsorption and precipitation experiments were conducted to recover pure Ni(II) compounds from the filtrate. Si(IV) was selectively loaded onto polyacrylamide, but this method did not efficiently filter the solution due to an increase in viscosity. The addition of Na₂CO₃ as a precipitant to the filtrate led to the simultaneous precipitation of Ni(II) and Si(IV). However, it was possible to recover nickel oxalate with a purity higher than 99.99% by selectively precipitating Ni(II) with the addition of Na₂C₂O₄ as a precipitant.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.100-108
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• 1986

This study was carried out in order to investigate protein cross-linking in freeze-dried meat of flounder (Limanda herzensteini). Changes in solubility or extractability of proteins and electrophoretic patterns of the extracted proteins were determined to monitor the cross-linking during the storage of freeze-dried meat. Development of nonenzymatic browning and the loss of in vitro protein digestibilily were also measured to assess their influences on the changes of functional and nutritional properties of proteins. In addition, the effects of lysine added, and removal of fat and water extractives were also mentioned. The extractability of protein decreased upon storage time and temperature, and the loss of solubility of myosin was evident. In case of the samples stored at $5^{\circ}C$ for 150 days, the extractability of protein decreased $26.4\%$, while that of the samples stored at $20^{\circ}C$ for 60 days decreased about $39.7\%$. And it was noted that the loss of solubility of myosin was $68.3\%$ and $98.1%$ for the same storage conditions, respectively. It was noteworthy that the samples treated with $L-lysine{\cdot}HCl$ seemed to prevent more or less the loss of protein solubility, in that, even stored at $20^{\circ}C$ for 120 days, revealed only $57.03\%$ decrease. The nonenzymatic browning was proceeded with the increase of storage temperature, especially, in the samples treated with glucose. This suggests that the decrease in extractibility of myosin was accompanied by the extent of browning. But the browning was retarded in defatted samples. The in vitro apparent protein digestibility was also higher in the samples defatted or water extracted. It was suggested from these results that changes in properties of proteins in freeze dried fish meat were led by the protein cross-linking which was attributed to Maillard type of reactions and protein-lipid interactions.

• YAKHAK HOEJI
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• v.41 no.3
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• pp.305-311
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• 1997

Sustained release-microspheres and immediate release-pellets were prepared to develop a controlled release multiparticulate system containing both water soluble and insoluble dr ug. Pseudoephedrin.HCl (EPD) and terfenadine (TRF) were used as model drugs, respectively. Sustained release-EPD microspheres were prepared by solvent evaporation method using Eudragit RL or RS as a matrix combined with pH-insensitive film coating. Smaller EPD microspheres were obtained when smaller amount of Eudragit as a matrix material or larger amount of magnesium stearate as a dispersing agent was used. However the obtained microspheres did not show syfficient sustained release characteristics. About 97% of EPD was released after 1 hr irrespective of matrix material used. Subsequent coating of the microspheres with pH-insensitive polymer such as Eudragit RS or ethylcelulose (EC) resulted good sustained in 37.5, 73.3 and 92.0% release of encapsulated EPD in distilled water after 1, 3 abd 7 hr, respectively. It corresponds to mean dissolution time (MDT) of 2.3 hr, which is much larger than that of un-coated EPD microspheres (0.0048 hr). Immediate release TRF pellets were prepared by spherically agglomerated crystallization using Eudragit E as an inert matrix and methylene chloride as a liquid binder. Using Eudragit E alone as a matrix resulted in satisfactory physical properties of the pellets such as sphericity, surface texture and flowability, but led to slower release of TRF from pellets than un-modified TRF powder (MDT of 1.70 vs 1.43 hr in pH 1.2 dissolution medium). Introducing propylene glycol or sodium lauryl sulfate as an emulsifier brought about faster release of TRF from pellets (MDT of 1.14 and 0.95 hr, respectively). In conclusion, microencapsulation by solvent evaporation combined with film coating and spherically agglomerated crystallization were successfully utilized to prepare controlled release multiparticulate system composed of sustained release EPD-microspheres and immediate release TRF pellets.

• The Korean Journal of Mycology
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• v.22 no.2
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• pp.122-129
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• 1994

The role of metal ions for the activity of the mitochondrial $F_1-ATPase$ was studied. Removal of non-heme iron ion from the mitochondria by dialysis against chelating agents, 10 mM ethylenediaminetetraacetic acid(EDTA) and 10 mM o-phenanthroline(o-Phe), led to 56% and 49% inactivation of the enzyme, respectively. The enzyme dialyzed against EDTA was reactivated 81% by the addition of 0.5 mM $Fe^{3+}$ and 70% by 0.5 mM $Mg^{2+}$. But, $Fe^{2+}$ did not reactivate the enzyme. Coexistence of 0.5 mM $Fe^{2+}$ and 0.5 mM $Mg^{2+}$ resulted in 95% reactivation of the enzyme, while $Fe^{3+}$ with 0.5 mM $Mg^{2+}$ did not reactivate the enzyme like the effect of $Fe^{2+}$ alone. The enzyme dialyzed against o-Phe showed the similar results. These data showed that $Fe^{3+}$ is predominantly required for the activity of the mitochondrial $F_1-ATPase$ in Lentinus edodes and stimulated the activity of it by $Mg^{2+}$. $Fe^{3+}$ and $Mg^{2+}$ increased enzyme's affinity for substrate, decreasing the Km value 1.67 mM to 0.65 mM.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.301-309
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• 2016

To facilitate the effective use of butter clam shell as a natural calcium resource, we determined the optimal conditions for calcium lactate (BCCL) preparation with high solubility using response surface methodology (RSM). The polynomial models developed by RSM for pH, solubility and yield were highly effective in describing the relationships between factors (P<0.05). Increased molar ratios of calcined powder (BCCP) from butter clam shell led to reduced solubility, yield, color values and overall quality. The critical values of multiple response optimization to independent variables were 1.75 M and 0.94 M for lactic acid and BCCP, respectively. The actual values (pH 7.23, 97.42% for solubility and 423.22% for yield) under optimization conditions were similar to the predicted values. White indices of BCCLs were in the range of 86.70–90.86. Therefore, organic acid treatment improved color value. The buffering capacity of BCCLs was strong, at pH 2.82 to 3.80, upon the addition of less than 2 mL of 1 N HCl. The calcium content and solubility of BCCLs were 6.2–16.7 g/100 g and 93.6-98.5%, respectively. Fourier transform analysis of infrared spectroscopy data identified BCCL as calcium lactate pentahydrate, and the analysis of microstructure by field emission scanning electron microscopy revealed an irregular form.