• Bulletin of the Korean Chemical Society
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• v.5 no.1
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• pp.21-23
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• 1984

The addition reactions of thioglycolic acid to ${\omega}$, ${\omega}$-diacetylstyrene derivatives were investigated. ${\omega}$, ${\omega}$-Diacetylstyrene derivatives easily undergo addition reactions with thioglycolic acid to form s-(2, 2-diacetyl-1-phenylethyl)-thiogycolic acid, s-[2,2-diacetyl-1-(methyl) phenylethyl]-thioglycolic acid, s-[2,2-diacetyl-1-(p-methoxy) phenylethyl]-thioglycolic acid and s-[2,2-diacetyl-1-(p-chloro) phenylethyl]-thioglycolic acid, respectively. The structures of these compounds were identified by neutralization equivalent, UV, IR, and NMR spectral data.

• Journal of the Korean Applied Science and Technology
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• v.28 no.1
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• pp.35-47
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• 2011

For the synthesis of water soluble acrylic modified epoxyester resin, fatty acid/epoxy ratio of 50/50 was used, and introduced maleic anhydride. Ratio of styrene/acrylic acid of acrylic monomers was fixed 85/15 and ratio of epoxyester/acrylic monomer was controlled 80/20, 75/25, 70/30, 65/35, and degree of neutralization were changed 65%, 80%, to 100%. As a result, 40% solids acrylic modified epoxyester resins were synthesized. Resins were evaluated water soluble stability, drying time, water resistant, storage stability and physical properties. And the white paints were prepared, and were evaluated viscosity, drying time, water resistance, adhesion, sagging, spray workability, gloss, salt spray resistance, skinning, whiteness and flash rust. As a result, the degree of neutralization of 100% and the ratio of epoxyester/acrylic monomer of 75/25 showed the best properties.

• Elastomers and Composites
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• v.34 no.5
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• pp.399-406
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• 1999

Polyurethane (PU) prepolymers were synthesized from polytetramethylene ether glycol (PTMG), 4,4'-diphenylmethane diisocyanate (MDI), toluene 2,4-diisocyanate (TDI) and isophoron diisocyanate (IPDI). After chain extention using dimethyol propionic acid (DMPA), aqueous polyurethane anionomers were prepared from triethyl amine (TEA) as a neutralizer. The effect of the content of chain extender and the degree of neutralization on the state of emulsification, adhesive strength, viscosity, glass transition temperature and physical properties of emulsion cast film were investigated using UTM, Viscometer and DSC.

• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.56-63
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• 1996

The results of the water purification studies using water parsley (Oenanthe javanica) were obtained as follows. The removal rate of nutrient salts increased with longer plant growth periods. The results of this study use the assumption, log(T+1) = $K(C_0-C)^A$, based on Prakish's Theory. The initial concentration was calculated from experimental data. A and K are closely related to the initial concentration. It is possible to model the concentration of residual salts, as time goes by, if concentration is constant. It was observed that water parsley neutralizes acid and alkali substances promptly. The maximum suitable neutralization period is 48 hours. But water parsley withered up in strong acid and alkali solutions within a week. The removal efficiency of Cd progresses in 2 steps, which are unrelated to the initial concentration of Cd. The first part of the curve shows the concentration rapid rate of Cd removal, followed by a levelling off. The removal rate of $NO_x-N$ in the sample water tank containing 0.5 ppm Cd was between 50~80% but the removal rate was less than 20% for the higher concentration. On the other hand, increased amounts of $PO_4-P$ in the sample water tank from the third day on suspected that $PO_4-P$ was desorbed from the water parsley. The accumulation efficiency of Cd in plant was increased in proportion to the initial concentration of Cd. The accumulation phenomenon was observed in the tanks more than 50~100 times.

• Membrane Journal
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• v.6 no.4
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• pp.250-257
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• 1996

Surface crosslinked chitosan composite membranes were prepared with glutaraldehyde and surfuric acid. Effects of neutralization for complex between chitosan and acetic acid and of water permeability for substrate membranes on pervaporation performance were investigated. For ionically crosskinked membranes, effect of active layer thickness on separation factor of water/ethanol mixture was studied. With increasing the water permeability of the substrate, the membrane showed an increased separation factor, while it maintained a constant permeate flux. Neutralized chitosan composite membranes revealed a decreased separation factor and a constant permeate flux. When the thickness of the active layer increased, an optimum crosslinking time to achieve higher separation factor shifted to a prolonged times.

• Journal of Korean Society of Disaster and Security
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• v.17 no.1
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• pp.27-35
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• 2024

This paper presents experimental research results to evaluate the applicability of chemical neutralization reaction and ultrasonic wave to remove cement paste and mortar attached to the surface of recycled aggregate. In order to derive optimal ultrasonic cleaning efficiency and chemical neutralization reaction, experiments were conducted using variables such as ultrasonic frequency and type of chemical solution. As a result, the optimal frequency was found to be 24 kHz, and immersion in a 15% hydrochloric acid solution for 30 minutes of stimulation showed the highest efficiency. In addition, the specific gravity, absorption rate, and wear rate of the quality-improved recycled coarse aggregate were similar to those of general aggregate and were found to satisfy all KS F 2527 standards. Therefore, it is believed that the recycled aggregate whose quality has been improved through the method proposed in this study can be used for concrete.

• Journal of Ginseng Research
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• v.22 no.3
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• pp.205-210
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• 1998

Glucosidic bonds at the C20 position of the sapogenins were hydrolyzed easily in the lower pH, higher temperatures and longer times to give prosapogenins and sugars. The glucosidic bond of saponin at the C3 of ginsenoside-Rb1, which is secondary carbon, was relatively stable due to the low electron density of -0.2. But the bond of saponin at the C20 position, which is tertiary carbon with the relatively high electron density of -0.3, was liable to be hydrolyzed even in weakly acidic solution by the increase of heating time. On the other hand, red ginseng contained 13.34 mg/g of citric acid, 8.78 mg/g of malonic acid, 3.70 mg/g of oxalic acid, 2.13 mg/g of malic acid and 0.44 mg/g of succinct acid. Ginseng saponins were very stable in ginseng extract neutralized with sodium carbonate or sodium bicarbonate corresponding to the equivalent amount of the total organic acid in the red ginseng.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.104-105
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• 2020

Red mud is a highly alkaline waste by-product of the aluminum industry. Although recycling of red mud is being actively researched, a feasible technological solution has not been found yet. In this study, we propose that neutralization of red mud alkalinity could assist in its use as a construction material. Neutralized red mud ( pH 6-8) was prepared by adding sulfuric acid to liquefied red mud (pH 10-12). After adding liquid and neutralized red mud to the cement paste, the heat of hydration was measured. As a result of the experiment, the calorific value of the cement paste with liquid red mud was lowered and delayed compared to the cement paste with neutralized red mud.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1495-1500
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• 2008

In an attempt to develop a probiotic formulation for poultry feed, a number of lactic acid bacteria (LAB) were isolated from chicken intestinal specimens and a series of in vitro experiments were performed to evaluate their efficacy as a potential probiotic candidate. A total of 650 LAB strains were isolated and screened for their antagonistic potential against each other. Among all the isolates only three isolates (TMU121, 094 and 457) demonstrated a wide spectrum of inhibition and were thus selected for detailed investigations. All three selected isolates were able to inhibit the growth of E. coli and Salmonella species, although to variable extent. The nature of the inhibitory substance produced by the isolates TMU121 and 094 appeared to be associated with bacteriocin, as their activity was completely lost after treatment with proteolytic enzymes, while pH neutralization and catalase enzyme had no effect on the residual activity. In contrast, isolate TMU457 was able to resist the effect of proteolytic enzymes while pH neutralization completely destroyed its activity. Attempts were made to study the acid, bile tolerance and cell surface hydrophobicity of these isolates. TMU121 showed high bile salt tolerance (0.3%) and high cell surface hydrophobicity compared to the other two strains studied, while TMU094 appeared the most pH resistant strain. Based on these results, the three selected LAB isolates were considered as potential ingredients for a chicken probiotic feed formulation and were identified to species level based on their carbohydrate fermentation pattern by using API 50CH test kits. The three strains were identified as Lactobacillus fermentum TMU121, Lactobacillus rhamnosus TMU094, and Pediococcus pentosaceous TMU457.

• Corrosion Science and Technology
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• v.8 no.3
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• pp.110-115
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• 2009

At the onset of corrosion of steel in concrete, hydrogen ions usually evolve in the process of electrochemical reaction, thereby decreasing the pH of the pore solution, which can be buffered by cement hydration products, as being representatively illustrated by calcium hydroxide. Hence, a fall in the pH is dependent on properties of cement hydration (i.e. hydration products and degree of hydration). The present study tested acid neutralization capacity (ANC) of cementitious binders of OPC(Ordinary Portland Cement), 30% PFA(Pulverized Fuel Ash), 60% GGBS(Ground Granulated Blast Furnace Slag), 10% SF(Silica Fume) to quantify the resistance of cement matrix to a pH fall. Cement pastes were cast at 0.4 of a free W/C ratio with 1.5% chlorides by weight of binder in cast. Powder samples obtained crushed and ground specimen after 200 days of curing were diluted in still water combined with different levels of 1M nitric acid solution, ranging from 0.5 to 20 mol/kg. Then, the pH of diluted solution was monitored until any further change in the pH did not take place. It was seen that the pH of the diluted solution gradually decreased as the molar amount of nitric acid increased. At some particular values of the pH, however, a decrease in the pH was marginal, which can be expressed in the peak resistances to a pH fall in the ANC curve. The peaks occurred at the variations in the pH, depending on binder type, but commonly at about 12.5 in the pH, indicate a resistance of precipitated calcium hydroxide. The measurement of water soluble chloride at the end of test showed that the amount of free chloride was significantly increased at the pH corresponding to the peaks in the ANC curve, which may reflect the adsorption of hydration products to chlorides.