• Title/Summary/Keyword: acidic condition

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Removal Properties of Chromium by 3 Different Carbon Adsorbents (3종의 탄소계 흡착제를 이용한 크롬 제거 특성)

  • Jung, Yong-Jun;Kim, Tae-Kyung
    • Journal of Wetlands Research
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    • v.19 no.2
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    • pp.246-251
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    • 2017
  • This study was carried out to evaluate the possibility of Chromium removal by 3 different kinds of adsorbents, where activated carbon(AC), carbon nanotube(CNT) and layered double hydroxides(LDHs) were employed. The highest surface area was shown in AC and pore volume was in CNT which were $1028.1m^2{\cdot}g^{-1}$ and $0.829cm^2{\cdot}g^{-1}$, respectively. AC and CNT are composed of more than 99% carbon. AC has shown the possibility of chromium removal more than 80.2% under the acidic pH condition.

The Study of Cochineal Dyeing. (코치닐의 염색성에 관한 연구)

  • 주영주;소황옥
    • Textile Coloration and Finishing
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    • v.10 no.1
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    • pp.11-19
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    • 1998
  • For the purpose of standardization and practicability of dyeing by natural dyes, the mordanting and dyeing properties of cochineal and carminic acid were studied. Appropriate extraction, dyeing and mordanting condition of cochineal were determined, and the effect of mordanting method on dye uptake and color fastness of dyed fabric was investigated. The maximum absorbance of cochineal solution was 495nm, carminic acid was 533nm and 577nm. The color of carminic acid solution was affected by pH 6~9. The optimum temperature to extract cochineal was $80-100^\circ{C}$ and dyeing solution for 1 hour. And effective dyeing time to silk was 60min. Effective mordanting temperature was $80^\circ{C}$, and its time was 30min. In case mordants concentration, the maximum absorbance of Sn solution was 3%, K, Cu and Cr were in 1%. K/S value of dyeing fabrics was recoginazed by mordant treatment, specially Fe, Sn, Al, Cu. In the case of cochineal light fastness was increased by mordant treatment, specially Fe treatment. Perspiration fastness was good in acidic solution than in alkaline solution and perspiration fastness of cochineal was poor. Fastness of abrasion and dry-cleaning were good and these fastness improvement were generally effective for post-mordanting treatment.

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Effect of Chitosan and Mordant Treatments on the Color Change of Cotton and Nylon Fabrics Dyed using Japanese Pagoda Tree (면(棉)과 나일론 직물(織物)의 괴화 염색(槐花 染色)에서 Chitosan 처리(處理)와 매염(媒染)이 색상(色相)에 미치는 영향(影響))

  • Hwang, Hui-Youn;Choi, Jeong-Im;Jeon, Dong-Won
    • Journal of Fashion Business
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    • v.10 no.2
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    • pp.18-26
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    • 2006
  • In this study, the effects of chitosan pre-treatment on the mordanting effect and dyeability were investigated in the dyeing using Japanese pagoda tree. The chitosan treatment effects were evaluated mainly focused on the colors after dyeing of cotton and nylon fabrics which were treated with acidic aqueous solution of chitosan. In the case of chitosan untreated fabrics, the mordanting effects on the cotton and nylon were insignificant and the dyeability was very low. Regardless of the mordant types(Al, Sn, and Fe), the dyed fabrics exhibited almost identical yellowish colors. In the case of chitosan treated fabrics, dark colors were obtained compared to the case of chitosan untreated and ${\Delta}E$ values were increased significantly. In cotton fabrics, the most excellent result was obtained under the condition of unmordanted and chitosan treated fabrics. This verifies the fact that routin coloring matters establish direct linkages with the chitosan components, which exhibit cationic nature, easily. In nylon fabrics, the effects of mordanting treatment and chitosan treatment are so insignificant that the routin coloring matters are presumed to establish direct dyeing with the nylon molecular chains.

Characteristics of improved Kochujang (개량식 고추장의 특성)

  • Woo, Dong-Ho;Kim, Ze-Uook
    • Applied Biological Chemistry
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    • v.33 no.2
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    • pp.161-168
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    • 1990
  • In order to investigate systematically characteristics of improved Kochujang in comparision with traditional Kochujang, changes of components in curing of two Kochujangs, enzyme activities of koji and Meju, and effects of salt and red pepper were measured. And it was found that the large differences of amino nitrogen and reducing sugar contents were appeared in the initial stage of the curing period, but the changes were parallel thereafter. The protease activity of koji was maximum in weak acidic pH and that of Meju was maximum in neutral pH. The optimum condition of substrate digestion was three hours at $60^{\circ}C$, and that was more effective than curing at room temperature. The activities of protease and saccharogenic amylase were decreased remarkably by adding salt and red pepper, Therefore, to decompose starch and protein effectively, the addition of salt and red pepper after substrate digestion was more favorable.

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The Characterization and Activity Changes of Phosphatases in Amoeba sp. to the Light Stimuli and Its Response Pattern (광자극에 대한 Amoeba 의 반응양상과 phosphatase 의 특성 및 활성도 변화)

  • Chang, Nam-Kee;Chai-Seong Lim;Jin-Ho Bae
    • The Korean Journal of Ecology
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    • v.14 no.1
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    • pp.101-111
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    • 1991
  • Amoeba sp. was cultured under the light and the dark conditions, and the activity of phosphatases was investigated. There was a linear correlation between the early reaction time and the activity of phosphatases when phosphatases were incubated at 30℃. Then the activity of acid phosphatase was about 2 times higher than that of alkaline phosphatase. The activity of phosphatase was optimal at pH 5.0 in acidic part and at pH 8.0 in alkaline part, respectively. The optimal temperature of phosphatases was near the 40℃. The isozyme patterns of cytoplasmic acid phosphatase were compared with those of membraneous one. Both the isozyme patterns were shown to bo polymorphic on the polyacyamide gel, but different band patterns were observed in the isozymes of the cytoplasmic and the membraneous acid phosphatases. The number of Amoeba sp. under the light stimulus for 48 hours decreased negative exponentially from the illumination. The activity of acid and alkaline phosphatases under the illumination of light incresed 1.7 and 1.5 times higher, respectively, than the activity of those under the dark condition. This result apperars to be related to the mechanism of the autophosphorylation.

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The Effect of Coating Thickness on the Electrochemical Properties of a Li-La-Ti-O-coated Li[Ni0.3Co0.4Mn0.3]O2 Cathode

  • Lee, Hye-Jin;Park, Yong-Joon
    • Bulletin of the Korean Chemical Society
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    • v.31 no.11
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    • pp.3233-3237
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    • 2010
  • A $Li[Ni_{0.3}Co_{0.4}Mn_{0.3}]O_2$ cathode was modified by coating with Li-La-Ti-O, and the effect of the coating thickness on their electrochemical properties was studied. The thickness of the coating on the surface of $Li[Ni_{0.3}Co_{0.4}Mn_{0.3}]O_2$ was increased by increasing the wt % of the coating material. The rate capability of the Li-La-Ti-O-coated electrode was superior to that of the pristine sample. 1- and 2-wt %-coated samples showed considerable improvement in capacity retention at high C rates. However, the rate capability of a 5-wt %-coated sample decreased. All the coated samples showed a high discharge capacity and slightly improved cyclic performance under a high cut-off voltage (4.8 V) condition. Results of a storage test confirmed that the Li-La-Ti-O coating layer was effective in suppressing the dissolution of the transition metals as it offered protection from the attack of the acidic electrolyte. In particular, the 2- and 5-wt %-coated samples showed a better protection effect than the 1-wt %-coated sample.

Resolution of Tocainide and Its Analogues on a Doubly Tethered N-CH3 Amide Chiral Stationary Phase Based on (+)-(18-Crown-6)-2,3,11,12-tetracarboxylic Acid

  • Lee, Kyu Jung;Tak, Kyung Mi;Hyun, Myung Ho
    • Bulletin of the Korean Chemical Society
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    • v.34 no.10
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    • pp.2978-2982
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    • 2013
  • A doubly tethered $N-CH_3$ amide chiral stationary phase (CSP 4) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid was applied to the resolution of an antiarrythmic agent, tocainide, and its analogues and the chromatographic resolution results were compared with those on a singly tethered N-H amide CSP (CSP 1), a singly tethered $N-CH_3$ amide CSP (CSP 2) and a doubly tethered N-H amide CSP (CSP 3) under an identical aqueous mobile phase condition. CSP 4 was found to be generally better than other CSPs in terms of the separation factors (${\alpha}$) and resolutions (RS). The retention times of analytes denoted by the retention factors ($k_1$) on CSP 4 were quite long compared to those on other CSPs because of the improved lipophilicity of CSP 4. The long retention times of analytes on CSP 4 were successfully controlled by the addition of a small amount of ammonium acetate to aqueous mobile phase without hurting the chiral recognition efficiency. The variation of the content and type of organic and acidic modifier in aqueous mobile phase was found not to change the chiral recognition efficiency significantly.

The Influence of Curing Conditions on the Composition of Essential Oil of Burley Tobacco Leaves (버어리종 잎담배의 건조조건이 정유성분 조성에 미치는 영향)

  • 배성국;김도연;이윤환;김영회
    • Journal of the Korean Society of Tobacco Science
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    • v.24 no.2
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    • pp.75-81
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    • 2002
  • This study was performed to investigate the influence of curing conditions on the composition of essential oil during curing process of burley tobacco leaves. The curing conditions were the primed curing in vinyl house (house-curing), air-curing barn (air-curing) and stalk-curing in conventional curing house (stalk-curing). Total 90 compounds are identified from the steam volatile oils of harvest and cured tobacco leaves by GC and GC-MS, respectively. The major components were neophytadiene, hexadecanoic acid, 3,8,13-duvatriene-1,5-diols, oxide-9-methylene-3,13-duvadienols, solanone, megastigma-4,6,8-trien-3-ones, phenylacetaldehyde, $\beta$-phenylethyl alcohol, indole, dihydroactinidiolide and phytol. The amount of alcoholic compounds was decreased more than approximately 50% in cured leaves without regard to the curing conditions. $\beta$-Phenylethyl alcohol and 3,8,13-duvatriene-1,5-diols were decreased more in air curing and stalk curing than in house curing. The amounts of phenylacetaldehyde, solanone, $\beta$-damascone, $\beta$ -damascenone, oxysolanone and megastigma-4,6,8-trien-3-ones as ketonic compounds, dihydroactinidiolide and indole as miscellaneous compounds in air-cured and stalk-cured tobacco leaves were 2 times higher than those in house-cured leaves, while esteric and acidic compounds were not changed largely in content by curing conditions.

Preparation of Fe(III)-Coated Starfish and Evaluation of the Removal Capacity of Copper (3가철 코팅 불가사리 흡착제 제조 및 구리 제거 특성 평가)

  • Yang, Jae-Kyu;Yu, Mok-Ryun;Lee, Seung-Mok
    • Journal of Korean Society on Water Environment
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    • v.22 no.1
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    • pp.172-176
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    • 2006
  • Fe(III)-Coated Star Fish (ICSF) was prepared by reaction of calcined Star Fish (SF) with Fe(III) solution at an elevated temperature. To investigate the stability of ICSF at acidic condition, dissolution of Fe was studied at pH 2 as a function of time. Extracted iron was negligible over the entire reaction time. This stability test suggests the applicability of ICSF in the treatment of wastewater even at low pH. Adsorption capacity of Cu(II) onto SF and ICSF was investigated in a batch and a column test. In the pH-edge adsorption, adsorption of copper onto SF and ICSF was quite similar over the entire pH range due to the presence of an important amount of Fe in SF itself. From the adsorption isotherm obtained with variation of the concentration of Cu(II), ICSF showed 1.6 times greater adsorption capacity than SF. Also, ICSF showed a greater removal capacity of Cu(II) in the column test.

A Study on Changes in Antibacterial Activity of Pepsin-hydrolyzed Bovine Apo-lactoferrin at Various Method for Pasteurizations and pH Values (살균방법 및 pH 조건에 따른 Pepsin-hydrolyzed Bovine Apo-lactoferrin의 항균성 변화에 관한 연구)

  • 김종우;이조윤;금종수;유대열
    • Food Science of Animal Resources
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    • v.18 no.2
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    • pp.157-163
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    • 1998
  • This study was carried out to examine that pepsin-hydrolyzed bovine lactoferrin has applicabilities which are market milk and dairy products. The stability of pepsin-hydrolyzed bovine apo-lactoferrin and the change of its antibacterial character has been studied under various method for pasteurization (LTLT; 65$^{\circ}C$ / 30min., HTST ; 75$^{\circ}C$ / 15sec., UHT ; 135$^{\circ}C$ / 3sec.) and pH Values (pH 2.0, pH 4.0, pH 6.8). The ehated samples were assayed for minimal bacteriocidal concentrations (MBCs) and bacteriocidal effect against E. coli. The results obtained were summarized as follows: After fractionation of pepsin-hydrolyzed bovine lactofeerin by gel filtration. several peptide fractions were found that had strong antibacterial activity. SDS-PAGE showed that the one of these fractions with strong antibacterial activity, which had a molecular mass a range of 30∼33KDa. The MBCs for pepsin-hydrolyzed bovine lactoferrin fraction No. 2 against E. coli required to cause complete inhibition of growth varied within the range of 200∼400 $\mu\textrm{g}$/ml, depending on heat treatments and pH conditions. The peptide fraction No. 2 showed strong bacteriocidal activity against E. coli at LTLT and HTST treatments under acidic pH conditions. and was reduced activity at UHT treatment under pH 6.8 condition.

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