• 제목/요약/키워드: Acidic property

검색결과 117건 처리시간 0.027초

구아바 잎 추출액을 이용한 직물의 천연염색(II) - 면직물의 염색성과 기능성 - (Natural Dyeing of Fabrics with Guava (Psidium guajava L.) Leaf Extract II - Dyeability and Functional Property of Cotton Fabrics -)

  • 한미란;이정숙
    • 한국의류산업학회지
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    • 제14권2호
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    • pp.320-330
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    • 2012
  • The natural dyeing of cotton fabrics with guava leaf extract was investigated. The temperature and time of dyeing are $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. In addition, the dyebath has been set at pH 5. Sn pre-mordanted fabrics showed the highest K/S value. Regardless of dyeing temperature, K/S values were high when Al, Cu, Fe-mordanted fabrics were dyed in post-mordanting and Sn-mordanted fabrics were dyed in pre-mordanting. The K/S value of dyeing fabrics could be increased with repetitive dyeing and mordanting. Compared to untreated dyed fabrics, the K/ S values of fabrics which had been treated with soybean milk, chitosan and gall nut tannin were increased. The changed surface colors of fabrics that were treated with soybean milk, chitosan and gall nut tannin were Y, YR and achromatic colors. Fabrics dyed with alkaline water extract showed reddish color. Sn-mordanted fabrics dyed with acidic water extract showed vivid yellowish color, and Cu-mordanted fabrics dyed with ethanol extract showed yellowish green color. In case of Sn-mordanted fabrics, the washing fastness was level 4. The dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness was better in dry rubbing than in wet rubbing of the fabrics. For the light fastness, all dyed fabrics showed low fastness. For antibacterial activity, the powder of guava leaf extract and the dyed fabrics with guava leaf extract showed 99.9% of high antibacterial activity. All dyed fabrics showed higher deodorization and UV protection rate than control fabric.

SUPPRESSION OF HYDROGEN CONSUMING BACTERIA IN ANAEROBIC HYDROGEN FERMENTATION

  • Park, Woo-Shin;Jang, Nam-J.;Hyun, Seung-H.;Kim, In-S.
    • Environmental Engineering Research
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    • 제10권4호
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    • pp.181-190
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    • 2005
  • Severe loss or hydrogen occurred in most anaerobic hydrogen fermentation reactors. Several selected methods were applied to suppress the consumption of hydrogen and increase the potential of production. As the first trial, pH shock was applied. The pH of reactor was dropped nearly to 3.0 by stopping alkalinity supply and on]y feeding glucose (5 g/L-d). As the pH was increase to $4.8{\pm}0.2,$ the degradation pathway was derived to solventogenesis resulting in disappearance of hydrogen in the headspace. In the aspect of bacterial community, methanogens weren't detected after 22 and 35 day, respectively. Even though, however, there was no methanogenic bacterium detected with fluorescence in-situ hybridization (FISH) method, hydrogen loss still occurred in the reactor showing a continuous increase of acetate when the pH was increased to $5.5{\pm}0.2$. This result was suggesting the possibility of the survival of spore fanning acetogenic bacteria enduring the severely acidic pH. As an alternative and additive method, nitrate was added in a batch experiment. It resulted in the increase of maximum hydrogen fraction from 29 (blank) to 61 % $(500\;mg\;NO_3/L)$. However, unfortunately, the loss of hydrogen occurred right after the depletion of nitrate by denitrification. In order to prevent the loss entangled with acetate formation, $CO_2$ scavenging in the headspace was applied to the hydrogen fermentation with heat-treated sludge since it was the primer of acetogenesis. As the $CO_2$ scavenging was applied, the maximum fraction of hydrogen was enhanced from 68 % to 87 %. And the loss of hydrogen could be protected effectively.

Effects of Caponization on Bone Characteristics and Histological Structure in Chickens

  • Chen, Kuo-Lung;Chang, Ming-Huang;Tsay, Shiow-Min;Hurng, Huaang-Youh;Chiou, Peter Wen-Shyg
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권2호
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    • pp.245-251
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    • 2006
  • The aim of this study was to investigate the effects of caponization on the bone characteristics, biomechanical property and histology in Taiwan country chickens fed to market age of 26 wks. Male Taiwan country chickens $D{\times}L_2$ were caponized or sham-operated at 8 wks of age, and selected healthy sham-operated and completely caponized chickens (prominent degenerated comb) were selected at 16 wks old and fed to 26 wks old for the trials. Fifteen intact male chickens (Intact), sham-operated chickens (Sham) and caponized chickens (Capon) were assigned for trial 1, and sixteen Intact and Capon were assigned for trial 2. Results in trial 1 showed that the abdominal fat and relative abdominal fat weights of Capon were significantly heavier than Intact and Sham (p<0.05), while the tibia weight and relative weight were the lightest (p<0.05). The tibia breaking strength, bending moment and stress of Capon were the poorest among groups (p<0.05). The trial 2 produced the similar observation that Capon were significantly lighter than Intact (p<0.05) in the tibia weight, relative tibia weight and their biomechanical properties. On histological determinations, Capon showed a thinner cartilage end and fewer chondrocytes (about 50%) and trabecular, and bigger marrow cavity; while decreased hemopoietic cells number with increased adipocytes than Intact observed by H&E stain and at low magnification. At high magnification, Capon showed a decrease in the chondrocyte size by 33 to 50%, with smaller nucleus located near the cell membrane, and exhibited monocellular form chondrocytes. Capon also showed a less strongly acidic sulfated mucosubstance with weaker dyeing property within cartilage zone, and smaller chondrocytes size by Alcian blue stain.

아미노산의 첨가가 anthocyanins 색소의 안정성과 항산화능력에 미치는 영향 (Effect of Amino Acids Addition on Stability and Antioxidative Property of Anthocyanins)

  • 오주경;임지영
    • 한국식품과학회지
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    • 제37권4호
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    • pp.562-566
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    • 2005
  • 천연색소이며 항산화제인 anthocyanins을 포도과피로부터 추출하여 7가지의 아미노산(Arg, Lys, Gly, Ile, Glu, Asp, Met)을 색소용액(pH 3.5)에 첨가한 후 저장기간($30^{\circ}C$, 14일)동안 일어나는 색소의 강도, 안정성 및 항산화능력의 변화를 측정하였다. 색소의 강도는 Asp의 첨가 시 유의적으로 증가하였으며, 색의 안정성은 염기성 아미노산을 제외한 중성, 산성 아미노산과, 함유황 아미노산인 Met의 첨가 시 대조구보다 유의적으로 증가하였다(p<0.05). DPPH법으로 측정한 anthocyanins 색소의 항산화능력은 저장기간 중 변화를 나타내지 않았으며 색소의 강도 감소에도 불구하고 항산화 능력은 유지되었다. 아미노산의 첨가는 DPPH법에 의한 anthocyanins 색소의 전자공여능을 측정한 경우 차이를 나타내지 않았으나, FRAP법으로 측정한 $Fe^{3+}$ 이온의 환원 능력은 Asp 또는 Met을 첨가한 경우 대조구에 비하여 증가하는 것으로 나타났다.

점토광물을 이용한 산소환원의 전기화학적 촉매성에 관한 연구 (The Electrocatalytic Reduction of Molecular Oxygen with Clay Modified Electrodes)

  • 오성훈;황진연;심윤보;이효민;윤지해
    • 한국광물학회지
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    • 제18권1호
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    • pp.1-9
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    • 2005
  • 몇 가지 점토광물과 메틸바이올로젠 또는 메틸렌블루를 함유시킨 점토수식전극을 이용하여 산소환원에 대한 전기화학적 촉매성을 검토하였다. 점토광물로는 Na-몬모릴로나이트, Ca-몬모릴로나이트, 카오리나이트를 사용하였다. 점토수식전극은 유리탄소전극 표면에 점토 현탁액을 입히고 메틸바이올로젠을 흡착시킨 것을 사용하였으며, 전기화학적 산소환원의 정도는 순환 전압전류법(cyclic voltammetry)으로 측정하였다. 실험결과, 다른 점토시료에 비하여 Na-몬모릴로나이트가 메틸바이올로젠의 흡착효과가 가장 크게 나타났고, 메틸바이올로젠을 흡착시킨 점토수식전극이 산소환원에 대한 촉매성이 월등히 우수하였다. 즉 촉매산소환원 피크가 242.6 mV 만큼 +방향으로 이동하였다. 메틸바이올로젠을 흡착시킨 점토수식전극이 메틸렌블루를 흡착시킨 점토수식전극보다 산소환원에 대한 촉매성이 더 높게 나타났다. Ca-몬모릴로나이트의 경우는 변화가 없었으나 Na-몬모릴로나이트의 구조는 메틸바이올로젠의 흡착으로 변화되었다. 메틸바이올로젠- Na-몬모릴로나이트 점토수식전극은 현탁액의 점토 농도가 약 0.87 g/10 mL이고. 메틸바이올로젠의 수용액의 농도가 대략 2.5 mM일 때 산소환원 촉매 효과가 가장 탁월하였다. 지지전해질의 pH에 따른 점토수식 전극의 산소 환원 촉매성은 중성의 pH 범위(6.3과 8.3)에서보다 산성인 pH 3.7과 알칼리성인 pH 12.7에서 월등히 크게 나타났다.

Effects of Ultra-high Pressure Homogenization on the Emulsifying Properties of Whey Protein Isolates under Various pH

  • Lee, Sang-Ho;Subirade, Muriel;Paquin, Paul
    • Food Science and Biotechnology
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    • 제17권2호
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    • pp.324-329
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    • 2008
  • The effect of ultra-high pressure homogenization on the emulsifying properties of whey protein was investigated in a model emulsion made with whey protein isolate and soya oil under various pH. The emulsifying properties, the average diameter of the oil droplets ($d_{vs}$), and the protein load, were measured for each emulsion produced at different homogenization pressures (50 to 200 MPa) and pH values (4.6 to 8.0). According to the results of variance analysis and response surface, the pH had more influence on oil droplet size and protein load than homogenization pressure. The model equations, which were obtained by response surface analysis, show that pH and homogenization pressure had the major effect on oil droplet size and protein load. Higher homogenization pressure decreased the average droplet size and the protein load. Homogenization at high pressure, as opposed to low pressure, causes no overprocessing, but the effect was pH-dependent. The average diameter of the oil droplets increased slightly by decreasing the pH from 8.0 to 6.5 and then increased dramatically toward the isoelectric point of whey protein (i.e., at pH 4.6). Moreover associated droplets were found at acidic pH and their size was increased at high temperature.

산화주석 얇은 막 전극에서의 이산화황 산화반응 (Electrochemical Oxidation of Sulfur Dioxide on Tin Oxide Thin Film Electrode)

  • 홍종인;백운기;김하석
    • 대한화학회지
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    • 제29권2호
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    • pp.172-177
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    • 1985
  • 안티몬이 첨가된 산화주석 얇은막 전극의 반도체적 성질을 조사하고 이산화황의 산화반응에 대한 이 전극의 전기화학적 촉매작용을 여러가지 조건하에서 조사하였다. $SO_2$(또는 아황산염)를 포함하는 전해질 용액의 pH가 증가함에 따라 점차로 낮은 전위에서 산화가 일어났으며 이 전극은 염기성 용액에서 $SO_3^=$의 산화에 대하여 뚜렷한 전기촉매 작용을 나타내었으며 이 전기촉매 작용은 백금이나 팔라듐 전극의 촉매작용과는 다른 특성을 보여주었다. 백금이나 팔라듐이 이 전극에 첨가된 경우에는 이들 금속이 전극표면에 노출된 양에 비례하는 효과만이 나타났다.

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프라노프로펜과 아스피린과의 상호작용 (Drug Interaction between Pranoprofen and Aspirin in Rats)

  • 최준식;최병철
    • 한국임상약학회지
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    • 제15권1호
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    • pp.50-54
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    • 2005
  • The purpose of this study is to investigate the effect of aspirin on the pharmacokinetics of pranoprofen by oral coadministration of pranoprofen (5 mg/kg) with aspirin (5, 10 and 20 mg/kg) in Sprague-Dawley rats. After oral coadministration of pranoprofen with aspirin, the area under the plasma concentration-time curves (AUC) of pranoprofen was increased significantly by 10 mg/kg (p<0.05) and 20 mg/kg (p<0.01) of aspirin coadministration, and peak concentrations ($C_{max}$) of pranoprofen was increased significantly by coadministration of 20 mg/kg aspirin (p<0.05) compared to pranoprofen alone. Relative bioavailabilities (RB${\%}$) of pranoprofen in coadmistration were higher (from 1.42 to 1.67 fold) than control. The half-lives ($t_{1/2}$) of pranoprofen in coadministration were increased significantly (p<0.05) by 20-mg/kg aspirin. Based on these results, we might be considered that the pharmacokinetics of pranoprofen would be affected by coadministration of aspirin, by inhibit its metabolism in the liver and the tubular secretion of the kidney with the same acidic property. It should take into consideration in dosage regimen of pranoprofen when coadministration of pranoprofen with aspirin in treatment of rheumatoid arthritis.

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Effect of pH on Swelling Property of Hyaluronic Acid Hydrogels for Smart Drug Delivery Systems

  • Kim, Jin-Tae;Lee, Deuk-Yong;Kim, Young-Hun;Lee, In-Kyu;Song, Yo-Seung
    • 센서학회지
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    • 제21권4호
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    • pp.256-262
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    • 2012
  • Hyaluronic acid(HA) hydrogels were synthesized by immersing HA microbeads in phosphate buffered saline solutions having different pH levels to assess the effect of pH on the swelling ratio of HA hydrogels for smart drug delivery systems. No beads were formed when the HA solution(below pH 9) was crosslinked with divinyl sulfone(DVS) because DVS is a basic solution. The variation regarding the size of the microbead was not significant, suggesting that the bead size is not a function of pH(10 ~ 14). However, the pore size of the microbeads decreased with increasing pH from 10 to 14, leading to the surface smoothness and dense network as a result of higher crosslinking. The swelling ratio of hydrogels increased when the pH rose from 2(acidic) to 6(neutral). Afterwards, it decreased with further increasing pH(basic). The lower swelling ratio may be due to the lack of ionization of the carboxyl groups. On the other hand, a higher swelling ratio is likely due to the increased electrostatic repulsions between negatively charged carboxyl groups on different chains. Experimental results suggested that pH-responsive HA hydrogels can be applicable to the controlled drug delivery systems.

저온균일침전법으로 제조된 TiO2 분말의 아크릴레진에서의 분산특성 및 광분해 효과 (Dispersion Properties and Photocatalytic Activities of TiO2 Powders Obtained by Homogeneous Precipitation Process at Low Temperature in a Acrylic Resin)

  • 우승희;김흥회;이창규
    • 한국분말재료학회지
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    • 제11권6호
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    • pp.503-509
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    • 2004
  • Dispersion stabilities and photocatalytic activities of rutile $TiO_{2}$ powders with unique nano-structure synthesized by homogeneous precipitation process at low temperature(HPPLT) have been investigated in the acrylic resin containing fluorostyrene in the range of 0~0.16 mole. Isoelectric point of $TiO_{2}$ in the acrylic resin placed in the neutral region whereas that of $TiO_{2}$ in the water placed in the acidic region, indicating that zeta potential and agglomeration of $TiO_{2}$ powder is strongly dependent on the pH and the type of solvent. To prepare an adhesion, an acrylic resin containing fluorostyrene was synthesized by a radical polymerization. The adhesion of coating layer was increased with increasing fluorostyrene's contents without changing the dispersion stabilities and degrading photocatalytic properties.