• Title/Summary/Keyword: Chemical effect

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Fabrication of Ag/In2O3/TiO2/HNTs hybrid-structured and plasma effect photocatalysts for enhanced charges transfer and photocatalytic activity

  • Wang, Huiqin;Wu, Dongyao;Liu, Chongyang;Guan, Jingru;Li, Jinze;Huo, Pengwei;Liu, Xinlin;Wang, Qian;Yan, Yongsheng
    • Journal of Industrial and Engineering Chemistry
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    • v.67
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    • pp.164-174
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    • 2018
  • The purpose of this work designed hybrid-structured and plasma effect photocatalyst of $Ag/In_2O_3/TiO_2/HNTs$ via sol-gel and photo-reduction methods. The structures, morphologies, optical and photoelectric performances of as-prepared photocatalysts were characterized via XRD, TEM, XPS, BET, UV-vis DRS, PL and photocurrents. The photocatalytic activity was evaluated by degradation of TC. The results showed that the hybrid-structure and plasma effect can effectively cause the multi-transfer of electrons and increase the separation rate of electron and hole pairs which obtained high photocatalytic activity. The photocatalytic degradation processes reveal that $^{\bullet}O_2{^-}$ and $h^+$ are major active species.

Prediction of a Strong Effect of a Wek Magnetic Field on Diffusion Assisted Reactions in Non Equilibrium Conditions

  • Kipriyanov, Alexey A. Jr.;Purtov, Peter A.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.3
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    • pp.1009-1014
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    • 2012
  • The influence of magnetic fields on chemical processes has long been the subject of interest to researchers. For this time numerous investigations show that commonly the effect of a magnetic field on chemical reactions is insignificant with impact less than 10 percent. However, there are some papers that point to the observation of external magnetic field effect on chemical and biochemical systems actually having a significant impact on the reactions. Thus, of great interest is an active search for rather simple but realistic models, that are based on physically explicit assumptions and able to account for a strong effect of low magnetic fields. The present work theoretically deals with two models explaining how an applied weak magnetic field might influence the steady state of a non-equilibrium chemical system. It is assumed that external magnetic field can have effect on the rates of radical reactions occurring in a system. This, in turn, leads to bifurcation of the nonequilibrium stationary state and, thus, to a drastic change in the properties of chemical systems (temperature and reagent concentration).

MODELLING STUDY OF THE EFFECT OF CHEMICAL ADDITIVES ON SOOT PRECURSORS REDUCTION

  • Park, J.K.
    • International Journal of Automotive Technology
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    • v.7 no.4
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    • pp.501-508
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    • 2006
  • The effect of chemical additives, such as dimethyl ether(DME), ethanol, carbon disulfide on the soot formation were examined numerically. ill this study, the Frenklach soot mechanism was used as a base mechanism to predict the soot formation in the ethane flame. The combination of Westbrook's DME mechanism, Marinov's ethanol mechanism, and chemical kinetic mechanism for hydrogen sulfide and carbon disulfide flames was made with the base mechanism because the DME, ethanol, $CS_2$ additives are added into the ethane fuel. CHEMKIN code was used as a numerical analysis software to simulate the effect of chemical additives on reduction of the polycyclic aromatic hydrocarbons(PAH's) which are soot precursors. From the numerical results it is observed that addition of DME, ethanol and $CS_2$ into ethane fuel can reduce PAH species significantly. That means theses additives can reduce soot formation significantly. Results also strongly suggest suppression of soot formation by these additives to be mainly a chemical effect. Hand OH radicals may be the key species to the reduction of PAH species for additives.

Chemical Substitution Effect on Energetic and Structural Differences between Ground and First Electronically Excited States of Thiophenoxyl Radicals

  • Yoon, Jun-Ho;Lim, Jeong Sik;Woo, Kyung Chul;Kim, Myung Soo;Kim, Sang Kyu
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.415-420
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    • 2013
  • Effect of chemical substitution at the para-position of the thiophenoxyl radical has been theoretically investigated in terms of energetics, structures, charge densities and orbital shapes for the ground and first electronically excited states. It is found that the adiabatic energy gap increases when $CH_3$ or F is substituted at the para-position. This change is attributed to the stabilization of the ground state of thiophenoxyl radical through the electron-donating effect of F or $CH_3$ group as the charge or spin of the singly-occupied molecular orbital is delocalized over the entire molecule especially in the ground state whereas in the excited state it is rather localized on sulfur and little affected by chemical substitutions. Quantitative comparison of predictions based on four different quantum-mechanical calculation methods is presented.

Effect of added mesophase pitch during the pitch synthesis reaction of PFO

  • Kim, Ji Hong;Kim, Jong Gu;Lee, Chul Wee;Lee, Ki Bong;Im, Ji Sun
    • Carbon letters
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    • v.23
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    • pp.48-54
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    • 2017
  • This research considers the effect of added mesophase pitch (MP) as an additive during the pitch synthesis reaction of pyrolyzed fuel oil (PFO). Two effects are generated by adding MP. One is an enhancement of thermal stability due to the high thermal property of the additive; the other is that the volatile compounds that were removed by vaporization of PFO during the thermal reaction can participate in the pitch synthesis reaction ($PFO{\rightarrow}pitch$) more efficiently. The effect differs according to the amount of the additive. When the amount of the additive is less than 7 wt%, the first effect is dominant, whereas the second effect is dominant when the additive amount exceeds 10 wt%.

KR-32158 protects heart-derived H9c2 cells from oxidative stress-induced cell death

  • Kim, Mi-Jeong;Jung, Yi-Sook;Kim, Sun-Ok;Lee, Dong-Ha;Lim, Hong;Yi, Kyu-Yang;Yoo, Sung-Eun;Lee, Soo-Hwan;Baik, Eun-Joo
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.131-131
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    • 2003
  • A benzopyranyl derivative, KR32158, synthesized as a plausible KATP opener, has been shown to exert cardioprotective effect in vivo myocardial infarction model. Myocardial ischemia, induced by oxidative stress, mental stress and fever, result in artheroscleosis, myocardial infarction and hypertrophy. In this study, we investigated in vitro effect of KR32158 by determining whether KR32158 produce cardioprotective effect against oxidative stress-induced death in heart-derived H9c2 cells. (omitted)

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The Effect of Hydrogen Chloride on the $NO_x$ Production in $H_2/HCl/Air$ Premixed Flame ($H_2/HCl/Air$ 예혼합 화염의 질소산화물 생성에서 염화수소의 영향)

  • Kwon, Young-Suk;Lee, Ki-Yong
    • Journal of the Korean Society of Combustion
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    • v.9 no.4
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    • pp.28-34
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    • 2004
  • Numerical simulations of freely propagating flames burning $H_2/HCl/Air$ Air mixtures were performed at atmospheric pressure in order to understand the effect of hydrogen chloride on flame structures. The chemical and physical effects of hydrogen chloride on flame structures were observed. A chemical kinetic mechanism was developed, which involved 26 gas-phase species and 198 forward elementary reactions. Under several equivalence ratios the flame speeds were calculated and compared with those obtained from the experiments, the results of which were in good agreement. As hydrogen chloride as additive was added into $H_2/Air$ flame, the flame speed, radical concentration and NO production rate were decreased. The chemical effect of hydrogen chloride caused the reduction of radical concentration, and then the decrease of the net rate of NO production. It was found that the influence in the reduction of $EI_{NO}$ with the addition of hydrogen chloride was attributed more due to the chemical effect than the physical effect.

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The Effect of Ruthenium Red on the Capsaicin-Induced Antinociception in vivo

  • Lee, Bu-Yean;Jung, Yi-Sook;Choi, Jin-Il;Kong, Jae-Yang
    • Biomolecules & Therapeutics
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    • v.3 no.1
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    • pp.54-57
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    • 1995
  • The effect of Ruthenium Red on the antinociceptive action of capsaicinoids was investigated using tail-flick test in mice. Capsaicin and KR-25018, when administered subcutaneously, had a potent antinociceptive effect against noxious heat stimulus. Ruthenium Red which is known to block the calcium channel coupled to the capsaicin receptor, when injected intraperitoneally more than 5 mg/kg, showed severe sedation and apparent antinociceptive effect against noxious heat stimulus. The 2.5 mg/kg Ruthenium Red, at which dose any significant sedative effect was not shown, had no effect on the antinociceptive effects of capsaicin and KR-25018. Considering this result, the antinociceptive effect of capsaicinoid may not be related to the Ruthenium Red sensitive calcium channel which is activated by capsaicin.

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The Study of Effects of Additives on the NOx Formation in $H_{2}/O_{2}/N_{2}$ Premixed Flames with Oxygen Enrichments (산소부화된 $H_{2}/O_{2}/N_{2}$ 예혼합 화염에서 첨가제가 NOx 생성에 미치는 영향 연구)

  • Lee, Ki-Yong;Kwon, Young-Suk
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.241-246
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    • 2003
  • Numerical simulations are performed at atmospheric pressure in order to understand the effect of additives on flame speed and the NOx formation in freely propagating $H_{2}/O_{2}/N_{2}$ flames with oxygen enrichments. A chemical kinetic mechanism is developed, which involves 26 gas-phase species and 99 reactions. Under several equivalence ratios and oxygen enrichments, flame speeds are calculated and compared with those obtained from the experiments, the results of which is in good agreement. As hydrogen chloride as additive is added into $H_{2}/O_{2}/N_{2}$ flames with low oxygen enrichments, its chemical effect causes the decrease of flame speed, radical concentration, and the NO production rate. It is found that the chemical effect of additive has much more influence on the reduction of EINO than its physical effect. However, in flames with very high flame temperature the physical effect rather than the chemical effect becomes more important on the reduction of EINO.

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The Effect of HCl on the NOx Reduction in $H_2/HCl/Air$ Premixed Flame ($H_2/HCl/Air$ 예혼합 화염에서 NOx 저감을 위한 HCl의 효과)

  • Lee, Ki-Yong;Kwon, Young-Suk;Sin, Sung-Su
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.2180-2185
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    • 2003
  • Numerical simulations of freely propagating flames burning $H_2/HCl/Air$ mixtures are performed at atmospheric pressure in order to understand the effect of HCl on the NOx reduction. A chemical kinetic mechanism is developed, which involves 26 gas-phase species and 99 reactions. Under several equivalence ratios the flame speeds are calculated and compared with those obtained from the experiments, the results of which is in good agreement. As HCl is added into $H_2/Air$ flame as additive, its chemical effect causes the reduction of radicals (H, OH, and O), and then the decrease of the net rate of NO production. It is found that the chemical effect of additive has much more influence on the reduction of EINO than its physical effect.

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