• 제목/요약/키워드: Acidic treatment

검색결과 579건 처리시간 0.027초

표면처리된 탄소나노튜브의 질소 및 산소관능기 도입에 따른 전기화학적 특성 (Combined effect of nitrogen- and oxygen functional groups on electrochemical performance of surface treated multi-walled carbon nanotubes)

  • 김지일;박수진
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.214.1-214.1
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    • 2011
  • In this work, the electrochemical properties of the surface treated multi-walled carbon nanotubes (MWNTs) are investigated for supercapacitors. Nitrogen- and oxygen functional groups containing MWNTs are prepared by nitrogen precursors and acidic treatment, respectively. The surface properties of the MWNTs are confirmed by X-ray photoelectron spectroscopy (XPS) and Zeta-potential measurements. The electrochemical properties of the MWNTs are investigated by cyclic voltammetry, impedance spectra, and charge-discharge cycling performance in 1 M $H_2SO_4$ at room temperature. As a result, these functionalized MWNTs lead to an increase in the specific capacitance as compared with the pristine MWNTs. It proposes that the pyridinic and pyridinic-N-oxides nitrogen species influence on the specific capacitance due to their positive charges, and thus an improved electron transfer at high current loads, since they are the most important functional groups affecting capacitive behaviors.

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In Vitro 상에서인 이온 존재 하에서의 칼슘 용해도를 증대시키는 펩타이드의 생산 (Production of Peptides Enhancing Calcium Solubility in the Presence of Phosphate Ions In Vitro)

  • 이윤동;이현수
    • 한국식품영양학회지
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    • 제10권4호
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    • pp.485-490
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    • 1997
  • 옥수수 글루텐을 식물성 효소인 파파인으로 가수분해하여 글루텐 펩타이드를 생산하였다. 생산된 글루펜 펩타이드류는 인이온 존재하에서 인이온과 칼슘이온과의 침전형성을 방지하여 칼슘의 용해성을 증진시켰다. 칼슘이온의 용해도는 8.3mg의 펩타이드 존재시 대조구에 비해 5.2배 증대되었다. 산성 아미노산의 함량이 매우 높은 이들 펩타이드류를 Delta pak 칼럼을 이용하여 분획하였으며 이들 분획 가운데 3번째 분획이 가장 높은 칼슘 용해성을 보였다.

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Identification of Degradation Products in the Phosphodiesterase (PDE-4) Inhibitor Roflumilast Using High Resolution Mass Spectrometry and Density Functional Theory Calculations

  • Paul, Saroj Kumar;Dash, Upendra N.
    • Mass Spectrometry Letters
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    • 제6권2호
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    • pp.38-42
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    • 2015
  • Roflumilast analogs are a group of drugs which act as selective photodiesterase (PDE-4) inhibitor for the treatment severe chronic pulmonary disease associated with chronic brochnonities. Structural identification of degradation products using high resolution mass spectrometry and theoretical investigation by density functional theory have been successfully carried out on roflumilast to identify four degradation products namely, 3,5-dichloropyridin-4-amine, N-(3,5-dichloropyridin-4-yl)-4-(difluoromethoxy)-3-hydroxy benzamide, N-(3,5-dichloropyridin-4-yl)-3-(cyclopropylmethoxy)-4-(difluoromethoxy) benzamide and 3-(cyclopropylmethoxy)-N-(3,5-dichloro-1-oxidopyridin-4-yl)-4-(difluoro methoxy) benzamide, generated in alkali, acidic and oxidative conditions.

Penicillium sp.-L4의 균성장 및 효소작용을 억제하는 $\beta$-glucosidase inhibitor의 분리 및 특성

  • 김무성;하성윤;전기붕;임달택;박병화;이보섭;이상린;최영길
    • 한국미생물·생명공학회지
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    • 제25권2호
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    • pp.189-196
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    • 1997
  • A producer of inhibitor against ${\beta}-glucosidase$ of Penicillium sp.-L4 was screened from Actinomycetes, and the isolated strain was identified as Streptomyces sp. The inhibitor produced was very stable against heat, acidic and alkaline conditions, proteolytic and amylolytic enzymes. The inhibotor was purified from culture broth through activated carbon treatment, ultrafiltration, anion and cation exchange, activated carbon columm, acetone precipitation and preparative HPLC. It showed inhibitory activities against a variety of dissacharide hydrolyzing enzymes produced by P.sp.-L4, and the mode of inhibition was competitive. Its structure and molecular formular was elucidated by IR, $^1H\;and\;^{13}C$ NMR and FAB/Mass spectrometry, which was identified as 1-deoxynojirimycin (dNM). dNM showed inhibitory effects on the cell growth and hydrolytic enzyme action of P.sp.-L4 on agar plate and infected lemon peel.

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Pseudoboehmite를 출발물질로한 kaolinite의 수열 합성 (Synthesis of kaolinite by hydrothermal reaction using pseudoboehmite as starting material)

  • 고태석
    • 한국결정성장학회지
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    • 제11권1호
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    • pp.33-37
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    • 2001
  • $213^{\circ}C$에서 깁사이트와 pseudoboehmite를 출발물질로 하여 산성도를 변화시켜 수열합성법에 의해서 카올리나이트를 합성하였다. 합성된 카올리나이트는 X-선회절 분석기와 적외선 분광광도계를 이용하여 결정화 과정을 조사하였으며 Hinckley 지수를 계산하였다. 산을 이용한 카올리나이트 합성은 출발물질의 용해를 촉진시켜 결정화하였다. 결정화 속도와 적층결함은 음이온의 종류, 산성도와 출발물질에 의존하였다.

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괴화의 염색성에 관한 연구 (The Study on the Mordanting and Dyeing Properties of Sophora Japonica L.)

  • 주영주;소황옥
    • 복식
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    • 제52권3호
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    • pp.19-27
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    • 2002
  • This paper surveys the mordanting and dyeing properties of Sophora japonica L. Appropriate extraction, dyeing and mordanting condition of Sophora japonica L. were determined, and the effect of mordanting method on dye uptake and color fastness of dyed fabric was investigated. The maximum absorbance of Sophora japonica L. solution was 367.6mn, rutin solution was 365.6mn. The color of Sophora japonica L. solution was affected at pH 2 and pH 8~9. The optimum temperature to extract Sophora japonica L. was during 1 hour in 8$0^{\circ}C$. The effective dyeing temperature and time of silk were 10$0^{\circ}C$, 60min. K/S value of dyeing fabrics was increased by pre-mordanting treatment, especially Fe, Sn, Cr. In the case of Sophora japonica L. light fastness was increased by Fe mordanting. Perspiration fastness was better in acidic solution than that in alkaline solution. Fastness to rubbing and dry-cleaning were good in general.

Characterizations of Membrane for Water Treatment: Surface Charge Analysis by Electrophoresis and Acidity Measurements

  • Yongki Shim;Lee, Sangyoup;Moon, Seung-Hyeon;Jaeweon Cho
    • Korean Membrane Journal
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    • 제2권1호
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    • pp.56-59
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    • 2000
  • The surface charge properties of a polymeric NF and a ceramic UF membranes were characterized in terms of zeta potential and acidity. Both the negative zeta potential and acidity values increased as pH increases due to ionizable acidic functional groups. Increased ionic strength reduced the acidity of the negatively-charged membrane surface as anticipated. Through these results, it can be envisioned are used to reject solutes with ionizable functional groups. Fouling of the negatively-charged membrane with natural organic matter (NOM) having a negative charge density was also investigated with respect to the surface charge. The surface charge of the NF membrane increased negatively when greater NOM adsorption onto the membrane surface occured.

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Self-organized Nanogels of Polysaccharide Derivatives in Anti-Cancer Drug Delivery

  • Park, Sin-Jung;Na, Kun
    • Journal of Pharmaceutical Investigation
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    • 제40권4호
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    • pp.201-212
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    • 2010
  • Self-organized nanogels from polysaccharide derivatives offer a promising approach in treatment of cancer due to their flexibility in chemistry and their ability to improve the therapeutic index of a drug by modifying biodistribution by their preferential localization at target sites and lower distribution in normal healthy tissues. These properties have promoted studies of active cancer targeting by self-organized nanogels for even better accumulation in solid tumors. However although many researchers have reported their potential by using cell culture systems and small animal tumor models in cancer therapy, these nanogels need more decoration such as conjugation with targeting moiety and endowment of stimuli-sensitivity for precise targeting of the cancer site. In this review, we summarize the recent efforts in developing novel targeting approaches via active endocytosis and stimuli-sensitive systems responding to hyperthermic or acidic tumor pH conditions.

이온교환을 이용한 음용수의 $NH_3-N$ 처리 (Treatment of $NH_3-N$ in Drinking Water Using Ion Exchange)

  • 채용곤
    • 환경위생공학
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    • 제23권1호
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    • pp.67-72
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    • 2008
  • Ion exchange performance to remove Ammonium in water was studied using commercially available strong acidic cationic exchange resin of $Na^+$ type in the batch and continuous column reactors. The performance was tested using the effluent concentration histories for continuous column or equilibrium concentrations for batch reactor as a function of time until resins were exhausted or reached ionic equilibrium between resin and solution. The results shoed that cationic exchange resin used in this study was more effective than activated carbon or zeolite for ammonium removal. Ammonium removal with the ion exchange resin temperature to be high qualitative recording minuteness but increases about seasonal change of temperature was judged with the public law where the adaptability is excellent. When the pH comes to be high at 11 degree, the ammonium was not effectively removed.

글리포세이트 음독 후 발생한 후두 부식손상 1예 (The Corrosive Laryngeal Injury of Glyphosate Surfactant Herbicide Intoxication : A Case Report and Review)

  • 주연희;김진평;박정제;우승훈
    • 대한후두음성언어의학회지
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    • 제22권2호
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    • pp.156-158
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    • 2011
  • Organophosphates are used as herbicides. Glyphosate is one of the acidic organophosphate solution of pH4.8-6. We experienced a case of laryngeal injury after glyphosate caustic ingestion. He had a mild respiratory distress, and a laryngeal granuloma was observed in endoscopy. He received treatment with oral steroid and PPI for two weeks, the laryngeal granuloma and respiratory distress were nearly disappeared. Therefore, we expect this case report to be helpful the therapeutic formulations in the damage of larynx due to glyphosate.

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