• Journal of Korean Society for Atmospheric Environment
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• v.22 no.4
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• pp.431-439
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• 2006

Catalytic oxidation of benzene, toluene and xylene (BTX) using regenerated metal oxide catalysts (ZnO-CuO, NiO, $Fe_2O_3$, ZnO, CrO) were investigated in a fixed bed flow reactor to evaluate their feasibility for the purpose of removing volatile organic compounds (VOCs). Four kinds of pre-treatment methods such as gas (air and hydrogen), acid aqueous solution, alkali aqueous solution and cleaning agent were used to find out the optimal regeneration conditions. The physico-chemical properties of the used and regenerated catalysts were characterized by BET and TPR (Temperature Programmed Reduction). The used catalysts showed high conversion ratio and the catalytic ability of toluene oxidation was in the order of ZnO-CuO>$Fe_2O_3$>NiO>ZnO>CrO. We found that the acid aqueous pre-treatment (0.1 N HNO$_3$) was the best way to enhance the catalytic activity of $Fe_2O_3$. In addition, air and hydrogen gas treatment were optimal for NiO and ZnO-CuO catalysts, respectively. Furthermore, the decomposition of BTX depends on the type of a catalyst and a gas molecule.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.425-429
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• 1987

The extra-cellular hemolysin from Bacillus thuringiensis subsp. israelensis was purified in the process of suiting with (NH$_4$)$_2$SO$_4$, Sephadex G-200 gel filtration, and DEAE-cellulose column chromatography. The purified hemolysin had molecular weight of approximately 47,000 dalton on SDS-polyacrylamide gel electrophoresis. The activity of purified hemolysin on human red blood cells was increased by thiol agents, but that was Inhibited by cholesterol, protease treatment, and metal salts such as CuSO$_4$, and FeSO$_4$, respectively.

• Textile Coloration and Finishing
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• v.14 no.5
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• pp.284-293
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• 2002

Nylon 6 and polyester taffeta fabrics are dyed in aqueous medium with vat dyes such as Indanthren Red FBB, Mikethren Blue ACE and Mikethren Blue HR varying the compositions of sodium hydrosulfite and NaOH. Also nylon UMF nonwoven and polyester UMF knitted fabrics are dyed with metal complex and disperse dyes as a reference, and the wash and rubbing fastnesses for these dyes are investigated. In vat dyeing of polyester and nylon taffeta, an optimum composition of sodium hydrosulfite/NaOH is existed at a range of 1∼2wt%/0.2wt%. A good build-up property for Mikethren Blue ACE on nylon 6 UMF nonwoven fabric is shown at high temperature. Vat dyeing of polyester with Mikethren Blue Ace shows a good color shade in a higher temperature, while dyeing with Mitsui Blue HR shows low temperatures. Vat dyes In dyeing of both nylon 6 UMF nonwoven and polyester UMF knitted fabrics have a better wash fastnesses compared with metal complex or disperse dyes.

• Korean Journal of Metals and Materials
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• v.48 no.6
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• pp.543-550
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• 2010

This paper investigated the synthesis conditions of nano-sized $TiO_2$ powder in a hydrothermal process at a temperature range of $100{\sim}180^{\circ}C$ considering the precipitation agent, precipitation pH, reaction temperature and time. Titanium hydroxide formed by $NH_4OH$ exhibited a lower crystallization temperature than that by NaOH and formed less aggregated $TiO_2$ particles. As the precipitation pH increased above 8, the shape of the particles changed from spherical to needle form, which appeared to be caused by dissolution and re-precipitation of the titanium hydroxide in an alkali environment.

• Resources Recycling
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• v.17 no.6
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• pp.68-78
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• 2008

Using a Pinus koraiensis and Pinus rigida which are normally being discarded in South Korea, optimal conditions of producing activated carbons have been studied to recycle as a higher value-added product. This study consists of two processes, the production process of charcoals from waste timbers by low temperature pyrolysis and the production process of activated carbons from the charcoals by chemical activation reaction. This paper deals with the production process of activated carbons from the charcoals by chemical activation reaction. As an alkali has been generally used as an activating agent, KOH and NaOH which react well with a carbon were used in this study. As a result of the experiments, it is confirmed that activated carbons made with KOH treatment had superior values in physicochemical properties to NaOH, showing that there was no remain of KOH at the surface of the charcoals while there was $3{\sim}4%$ of NaOH remaining after the experiments. Thus, it is concluded that KOH reacted more actively with a charcoal than NaOH. Moreover, it was also found that values in physicochemical properties when using a Pinus koraiensis are superior to the ones when using a Pinus rigida. The optimal mixing ratio of an activating agent to a charcoal was 400 wt.%. To improve the physicochemical properties, activated carbons were washed out by distilled water after neutralization with SM hydrochloric acid solution. When activated carbons were produced from a Pinus koraiensis in this optimal conditions, value of BET surface area was found to be approx. $2400\;m^2/g$.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.397-404
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• 2006

This paper investigates experimentally the effect of combined addition of expansive additive and shrinkage reducing agent(SRA) on setting time, compressive strength and drying shrinkage of concrete. An increase of EA and SRA content leads to a reduction in flowability, which causes the increase of superplasticizer dosage, while air content increases. For setting time, in spite of increased superplasticizer dosage, with the increase of EA and SRA, setting time shortens. This is due to the presence of alkali ion by SRA and the faster formation of ettringite. At dosage of 5.0% of EA, concrete has the highest compressive strength and above that dosage, compressive strength decreased. On the contrary, the increase of SRA dosage results in a decrease in compressive strength. Combined addition of EA of 5.0% and SRA of 1.0% shows a comparable strength with control concrete. For drying shrinkage, as expected, the increase of EA and SRA dosage leads to reduction of drying shrinkage markedly. Moreover, combined addition of EA and SRA has better drying shrinkage reduction effect than individual use of EA and SRA by as much as $5{\sim}16%$. Optimal combination of EA and SRA is fixed at 5.0% of EA and 0.5% of SRA based on the consideration of the effect of EA and SRA on fresh state, compressive strength and shrinkage of concrete.

• Journal of the Korean Chemical Society
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• v.4 no.1
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• pp.70-77
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• 1957

4,5-Diphenyl Imidazolone is synthesized from Benzoin, Urea, and Acetic acid catalyser. Nowadays, it is being used as an optical bleaching agent for wool and nylon textiles. Up to now, only one process of synthesis has been known. In order to find out the best conditions governing the yield were examined under various catalysers and conditions. In this experiment, the summary of results were as follows. a. On Acetic acid catalyser. The maximum yield conditions were mol ratio (Benzoin: Urea: Acetic acid) 1 : 2 : 14, Acetic acid concentration 99.9%. Reaction temperature 115$^{\circ}$. Under reaction time of 2 hours, above yield was 96.4%. b. On Mineral acid Catalyser. In using of Sulfonic acid, the color of solution was changed dark purlish black. With other mineral acid catalysers, in spite of increasing of temperature, it was proved that Benzoin floats on the solution, so that this reaction could not be continue. c. On Phosphoric acid catalyser. It was made clear that it can not be used for this reaction. d. On Sodium hydroxide catalyser. As one of Alkali catalyser, Sodium hydroxide was examined but this was unsuitable substance for this reaction. e. On Formic acid catalysers. The maximum yield conditions were mol ratio (Benzoin: Urea: Formic acid) 1: 2: 30. Formic acid concentration 85.%. Reaction temperature 150∼110$^{\circ}$. Under reaction time of 90 minutes, the best yield was 87%. Hereby, it was proved that organic acids such as Acetic acid and Formic acid can be used. When using Acetic acid, the yield was better than Formic acid, but it takes longer reaction time than Formic acid. About the fluorescent effect, the temperature of dye-bath must not be over 904,5-Diphenyl Imidazolone is synthesized from Benzoin, Urea, and Acetic acid catalyser. Nowadays, it is being used as an optical bleaching agent for wool and nylon textiles. Up to now, only one process of synthesis has been known. In order to find out the best conditions governing the yield were examined under various catalysers and conditions. In this experiment, the summary of results were as follows. a. On Acetic acid catalyser. The maximum yield conditions were mol ratio (Benzoin: Urea: Acetic acid) 1 : 2 : 14, Acetic acid concentration 99.9%. Reaction temperature 115$^{\circ}$. Under reaction time of 2 hours, above yield was 96.4%. b. On Mineral acid Catalyser. In using of Sulfonic acid, the color of solution was changed dark purlish black. With other mineral acid catalysers, in spite of increasing of temperature, it was proved that Benzoin floats on the solution, so that this reaction could not be continue. c. On Phosphoric acid catalyser. It was made clear that it can not be used for this reaction. d. On Sodium hydroxide catalyser. As one of Alkali catalyser, Sodium hydroxide was examined but this was unsuitable substance for this reaction. e. On Formic acid catalysers. The maximum yield conditions were mol ratio (Benzoin: Urea: Formic acid) 1: 2: 30. Formic acid concentration 85.%. Reaction temperature 150∼110$^{\circ}$. Under reaction time of 90 minutes, the best yield was 87%. Hereby, it was proved that organic acids such as Acetic acid and Formic acid can be used. When using Acetic acid, the yield was better than Formic acid, but it takes longer reaction time than Formic acid. About the fluorescent effect, the temperature of dye-bath must not be over 90$^{\circ}$. and the ratio of 4,5-Diphenyl Imidazolone and water should be from 1:50000. to 1:10000. It proved that the best effect on textiles, and the best condition were dye-temperature near 704,5-Diphenyl Imidazolone is synthesized from Benzoin, Urea, and Acetic acid catalyser. Nowadays, it is being used as an optical bleaching agent for wool and nylon textiles. Up to now, only one process of synthesis has been known. In order to find out the best conditions governing the yield were examined under various catalysers and conditions. In this experiment, the summary of results were as follows. a. On Acetic acid catalyser. The maximum yield conditions were mol ratio (Benzoin: Urea: Acetic acid) 1 : 2 : 14, Acetic acid concentration 99.9%. Reaction temperature 115$^{\circ}C$. . Under reaction time of 2 hours, above yield was 96.4%. b. On Mineral acid Catalyser. In using of Sulfonic acid, the color of solution was changed dark purlish black. With other mineral acid catalysers, in spite of increasing of temperature, it was proved that Benzoin floats on the solution, so that this reaction could not be continue. c. On Phosphoric acid catalyser. It was made clear that it can not be used for this reaction. d. On Sodium hydroxide catalyser. As one of Alkali catalyser, Sodium hydroxide was examined but this was unsuitable substance for this reaction. e. On Formic acid catalysers. The maximum yield conditions were mol ratio (Benzoin: Urea: Formic acid) 1: 2: 30. Formic acid concentration 85%. Reaction temperature 150∼110$^{\circ}C$. Under reaction time of 90 minutes, the best yield was 87%. Hereby, it was proved that organic acids such as Acetic acid and Formic acid can be used. When using Acetic acid, the yield was better than Formic acid, but it takes longer reaction time than Formic acid. About the fluorescent effect, the temperature of dye-bath must not be over 90$^{\circ}C$. and the ratio of 4,5-Diphenyl Imidazolone and water should be from 1:50000. to 1:10000. It proved that the best effect on textiles, and the best condition were dye-temperature near 70$^{\circ}C$. and dye-time 15 minutes. . and dye-time 15 minutes. . and the ratio of 4,5-Diphenyl Imidazolone and water should be from 1:50000. to 1:10000. It proved that the best effect on textiles, and the best condition were dye-temperature near 70$^{\circ}C$. and dye-time 15 minutes.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.540-547
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• 2001

An experiment was conducted to investigate the effects of environmentally friendly agents (yucca extract, mineral feed additive, acidifier, nonspecific immunostimulating anionic alkali solution) on the growth performance, nutrient digestibility, nutrient excretion and carcass characteristics in growing-finishing pigs. A total of 125 pigs were allotted into 5 treatments with 5 replications, 5 pigs per pen in a completely randomized block design. Dietary treatments consisted of 1) control: basal diet, 2) YE: basal diet+120 mg/kg of yucca extract, 3) MFA: basal diet+50 mg/kg of mineral feed additive, 4) NIS: basal diet+3% of NIS (nonspecific immunostimulating anionic alkali solution), and 5) Acidifier: basal diet+0.5% of acidifier (organic acid complex). During the growing phase of the feeding trial, There were no significant differences in average daily feed intake (ADFI) and feed conversion ratio (F/G) among treatments, but the Acidifier group showed higher average daily gain (ADG) than the MFA group (p<0.05). During the finishing phase, there were no significant differences in growth performance among treatments, however YE supplementation increased ADG and F/G by 3.1 and 6.15%, respectively, when compared to control group. Proximate nutrients (dry matter, DM; crude protein, CP; crude ash, CA; crude fat, CF; gross energy, GE; calcium, Ca and phosphorus, P) digestibility did not show any significant differences among the treatments. And there were no significant differences in DM, N and P excretion as well. The supplementation of environmentally friendly agents tended to increase carcass weight compared to control group. Pigs fed MFA showed significantly heavier (p<0.05) carcass weight than those fed control or Acidifier diets. Addition of these agents except for NIS to diet for growing-finishing pigs caused a similar feed cost/kg weight gain than control group. Therefore, present study suggested that the optimum environmentally friendly agent would be yucca extracts, considering the effects on growth performance, nutrient digestibility, nutrient excretion, carcass characteristics and feed cost in growing-finishing pigs.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.20-27
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• 2021

Effects of the etching treatment of SAPO-34 catalyst were investigated to improve the catalytic lifetime in DTO reaction. The aqueous NH3 solution was a more appropriate treatment agent which could control the degree of etching progress, compared to that of using a strong acid (HCl) or alkali (NaOH) solution. Therefore, the effect on characteristics and lifetime of SAPO-34 catalyst was observed using the treatment concentration and time of aqueous NH3 solution as variables. As the treatment concentration or time of aqueous NH3 solution increased, the growth of erosion was proceeded from the center of SAPO-34 crystal plane, and the acid site concentration and strength gradually decreased. Meanwhile, it was found that external surface area and mesopore volume of SAPO-34 catalyst increased at appropriate treatment conditions. When the treatment concentration and time were 0.05 M and 3 h, respectively, the lifetime of the treated SAPO-34 catalyst was the longest, and was significantly enhanced by ca. 36% (based on DME conversion of > 90%) compared to that of using the untreated catalyst. The model for the etching progress of SAPO-34 catalyst in a mild treatment process using aqueous NH3 solution was also proposed.

• Journal of Fashion Business
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• v.10 no.1
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• pp.120-131
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• 2006

Recently, it has been reported that chemical hair coloring can cause allergic reactions, the toxicity issue of chemical hair color was issued. Therefore, there is an increasing interest in the hair coloration technique using non-toxic and bio-compatible hair color gotten from natural resource. In this study, the possibility using fermented Indigo as natural hair coloring agent was investigated. Bleached hair samples were dyed using Indigo, and the effect of dyeing frequency, the physical change after dyeing, color, surface and cross-section characteristics, and tensile property were also studied. In addition, the protection property of cationic detergent finishing on damaged hair samples were also studied. The following conclusions are made; 1. While bleached hair samples with low value showed the negligible effect of repeated dyeing, bleached hair samples with high value showed the good effect of repeated dyeing. 2. Hair sample dyed with Indigo showed a high light-fastness, however, tensile strength and elongation showed very low values (high damage on hair sample). 3. Cationic detergent finishing did not affect on the colorfastness because of decoloration after dyeing, however, it increased the smoothness of hair sample, and therefore, can use as protectant of damaged hair. 4. Hair scale was damaged after dyeing. It seemed that the alkali, potassium carbonate, increased pH of dyeing bath to 11, as a result, the hair was swollen, weaken, and dissolved on the prolonged dyeing time. Dyed hair sample became stiff and fine. 5. The color difference was 4.62 (a high fastness value) in the test of sunlight exposure, shampoo, cationic detergent finishing, and acid perspiration fastness.