• 제목/요약/키워드: Chemical Effects

검색결과 8,791건 처리시간 0.047초

Chemical Composition of Artemisia argyi Extract (RW0117) and Protective Effects against Gastric Lesions in vivo

  • Lee, Jin Woo;Park, Se Hoon;Jegal, Chang Min;Choi, Keun Young;Jung, Hye Young;Choi, Jung A;Lee, Chan Kyu;Kim, Ho Kyong;Lee, Jung Suk;Lee, Il Kyun
    • Natural Product Sciences
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    • 제26권4호
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    • pp.268-278
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    • 2020
  • In this study, we investigated the chemical profile and effects of RW0117 (Artemisia argyi 65 .5 % ethanol extract) on gastric lesions in rats. We optimized and validated a method to obtain the chemical profile of RW0117. We then investigated the antioxidant and anti-inflammatory effects in vitro, and the protective effects on gastric lesions in vivo. The IC50 of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging considering the antioxidant effects of RW0117 was 166.55 ㎍/mL, and the IC50 of nitric oxide scavenging considering the anti-inflammatory effects was 41.16 ㎍/mL. Oral administration of RW0117 at lower concentrations (25, 50, 100 mg/kg) had similar or greater effects than the daily intake conversion concentration (115mg/kg) of a health functional food (Avexol®) in the acetic acid-induced ulcer and the ethanol-induced gastric injury rat models. In addition, oral administration of RW0117 increased the expression of prostaglandin E2, which enhances the protective effect in the gastric mucosa in the ethanol-induced gastric injury rat model. These results suggest that RW0117 may have potential therapeutic uses in the protection of the gastric mucosa.

3,6-Carbazole Incorporated into Polymer Effects on Solar Cells

  • Lee, Gang-Young;Cha, Hyojung;Park, Chan Eon;Park, Taiho
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.481.2-481.2
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    • 2014
  • Bulk hetero junction (BHJ) polymer solar cell (PSCs) is one of the most promising fields as alternative energy source. Especially, the development of new p-type conjugated polymer is one of the main issues to get core technology. In this study, we investigated the chemical doping effects of incorporating 3,6-carbazole units into conjugated polymers based on 2,7-carbazole. We assessed the structural effects of this chemical doping by measuring the photovoltaic device performance of the copolymers with and without annealing. Note that the use of nanostructures in the bulk heterojunction layer could be a major obstacle to commercialization because nano-morphologies are frequently unstable at high temperatures. Therefore, the development of thermally stable polymer:fullerene blends with optimized PCEs is an important goal in this area of research. We studied the morphologies of the copolymers incorporating 3,6-carbazole units resulting from thermal annealing to investigate the effects of the difference between the T g values of the 2,7-carbazole unit and the 3,6-carbazole unit.

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결정질 태양전지를 위한 HF 화학 패시베이션 연구 (A Study on HF Chemical Passivation for Crystalline Silicon Solar Cell Application)

  • 최정호;노시철;유동열;이진화;김영철;서화일
    • 반도체디스플레이기술학회지
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    • 제10권1호
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    • pp.51-55
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    • 2011
  • The surface passivation is one of the important methods that can improve the efficiency of solar cells and can be classified into two methods: wet-chemical passivation and film passivation. In this paper, chemical HF treatment were employed for the passivation of n-type silicon wafers and their effects were studied. To investigate film passivation effects, the silicon nitride films were also deposited by PECVD (plasma-enhanced chemical vapor deposition) on n-type silicon wafers treated with chemical HF. The minority carrier lifetime measurements were used for evaluation of the passivation characteristics in the all experiments steps. We confirmed that the minority carrier lifetime was improved with chemical HF treatment due to passivation effects by H-termination.

온도와 질량유속이 불화중수소 화학 레이저 성능에 미치는 영향 (Effects of Temperature and Mass Flux on Deuterium Fluoride Chemical Laser Performance)

  • 박병서;이정환
    • 한국군사과학기술학회지
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    • 제7권4호
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    • pp.100-106
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    • 2004
  • The effects of adiabatic flame temperature and mass flux on deuterium fluoride(DF) chemical laser performance were investigated. The power flux and specific power, which are important parameters containing the information of scaling effects of laser device magnitude, and chemical efficiency were selected as a judging parameter of DF laser performance. For the specific power, it was decreased by the increase of power flux of DF laser. Higher the adiabatic flame temperature of atomic fluorine generator, higher the chemical efficiency of DF laser was changed. It seems that the mass flux effect on the chemical efficiency is not remarkable.

새로운 pyrazole 유도체의 합성과 제초활성 (Synthesis of new pyrazoles and their herbicidal effects)

  • 전동주;이정노;김형래;송종환;황인택;유응걸
    • 농약과학회지
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    • 제3권1호
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    • pp.96-101
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    • 1999
  • 새로운 합성방법을 개발하여 pyrazolate 제초제의 곁가지를 변화시킨 새로운 구조의 3-trifluoro-methylpyrazole 유도체들과 4-benzenecarbinolpyrazole 유도체 등을 합성하여 전작과 답작상태에서 제초활성 시험을 하였다. 밭조건에서는 발아전처리의 경우 4 kg/ha의 약량에서도 제초효과를 나타내지 않았으며 발아후처리에서는 제초효과가 있었으나 미약하였다. 답작상태에서는 4 kg/ha의 약량에서 제초효과가 있었으며 특히 4-benzoylpyrazole의 benzene의 4위치에 electron-donating group인 methoxy가 치환된 화합물의 경우 활성과 선택성이 매우 좋았다. 그러나, methoxy가 두 개 이상 치환되거나 다른 electron-donating group인 sulfide기가 치환된 화합물들의 제초활성은 약하였다.

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Influence of "Historical Effects" on the Rheological Properties of a Polyacrylonitrile Copolymer Solution

  • Cheng, Yumin;Zhang, Huibo;Zhang, Shuangkun;Liu, Weiwei;Wang, Jing;Cheng, Run;Ryu, SeungKon;Jin, Riguang
    • Carbon letters
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    • 제14권1호
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    • pp.45-50
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    • 2013
  • Polyacrylonitrile (PAN) copolymers of different molecular weights were synthesized by a suspension polymerization and precipitation polymerization method. The rheology behaviors of the synthesized PAN copolymers were investigated in relation to their molecular weight, solid content and melting temperature. The influence of "historical effects" on the spinning solution of PAN was studied by analyzing the laws of viscosity considering the diversification time and temperature. The viscosity disciplines of each spinning solution conformed well to the rheological universal laws in a comparison of the suspension polymerization product with that of precipitation polymerization. Viscosity changes in the swelling process of dissolution were gentler in the suspension polymerization product; a small amount of water will quickly debase the solution viscosity, and high-speed mixing can greatly shorten the time required by the spinning solution to reach the final viscosity.

돼지분뇨의 간이건조 처리법과 비료로서의 효과 (Sun Curing Effects and Utilization of Pig Excreta as Fertilizer)

  • 성경일;홍병주;이영철
    • 한국초지조사료학회지
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    • 제13권3호
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    • pp.228-233
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    • 1993
  • Method for the sun curing dehydration of pig excreta by using vinyl house was described. We determined effects of the dehydrated pig excreta on the yields of whole crop corn and proximate chemical composition of whole crop corn. Pig excreta were dehydrated upto 15% of moisture content by the 3-4 days of sun curing dehydration in vinyl house in the summer period. There was no significant difference between the dehydrated pig excreta treatment and the chemical fertilizer treatment on dry matter(DM) content, DM yield and crude protein contents of whole crop corn. Ca and Mg contents by the dehydrated pig excreta treatment were lower than those by thechemical fertilizer treatment. In the contrast, K content by the dehydrated pig excreta treatment was higher than those by the chemical fertilizer treatment. and dehydrated pig excreta treatments were higher in K/Ca+Mg ratio than chemical fertilizer treatment. These results suggested the availability of the sun curing dehydration of pig excreta in vinyl house in small-scale animal industry. In addition, the dehydrated pig excreta treatment showen similar effects to the chemical fertilizer treatment on dry matter yields and contents of chemical composition of whole crop corn. These results suggest that using the sun curing dehydration of pig excreta could reduce the chemical fertilizer cost. However, we need more study to the relationship between the unbalanced mineral contents and animal health.

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