• 제목/요약/키워드: Chemical Reaction

검색결과 9,366건 처리시간 0.038초

환원온도가 Pt/MoO3/SiO2 촉매에서 iso-butene 의 골격 이성질화반응에 미치는 영향 (Effect of reduction Temperature on the Skeletal Isomerization of iso-butene over Pt/MoO3/SiO2 Catalyst)

  • 조새정;김성민;김동회;김성수;김진걸
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2004년도 추계학술대회
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    • pp.280-283
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    • 2004
  • Effect of H2 spillover rate as function of reduction temperature on reaction kinetics was evaluated. Reaction kinetics including yield, conversion, activation energy and selectivity of 1-butene isomerization over Pt/HxMoO/SiO were measured as reaction temperature was increased. While conversion of 1-butane was decreased, yield of iso-butene was increased. Two kinds of reaction mechanism were proposed from the change of selectivity as function of temperature.

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Photoinduced Electron Transfer From Aromatic Amines to Triplet States of $C_{60}$

  • Yahata, Yukio;Sasaki, Yoshiko;Fujitsuka, Mamoru;Ito, Osamu
    • Journal of Photoscience
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    • 제6권3호
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    • pp.117-121
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    • 1999
  • Photoinduced electron transfer of C60 has been studied by the laser photolysis measuring the transient absorption bands in near-IR region. The electron transfer aromatic amines via the triplet state of C60 is confirmed by the decay of the transient absorption bands of the triplet state of C60 and the rise of the anion radical of C60 and the cation radicals of amines. The rate and efficiency of electron transfer are strongly affected by the donor ability of amines and polarity of solvents. Back electron-transfer kinetics is also strongly affected by the solvent polarity.

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SORET AND ELECTROMAGNETIC RADIATION EFFECT OF MHD MICRO POLAR FLUID PAST A POROUS MEDIUM IN THE PRESENCE OF CHEMICAL REACTION

  • SHEEBA JULIET S.;VIDHYA, M.
    • Journal of applied mathematics & informatics
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    • 제41권5호
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    • pp.1085-1102
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    • 2023
  • In this study the magneto hydrodynamic (MHD) micro polar fluid flow of a viscous incompressible fluid past a porous medium in the presence of chemical reaction is considered. This work is devoted to investigate the Soret effect and Electromagnetic radiation effect and analyze analytically. In the energy equation the applied magnetic field strength and in the concentration equation the Soret effect are incorporated. The basic PDE (partial differential equations) are reduced to ODE (ordinary differential equations) using non dimensional variables. Then the analytical solution of the dimensionless equations are found using perturbation technique. The features of the fluid flow parameters are analyzed, discussed and explained graphically. The graphical solutions are found using MATLAB R2019b. Skin friction coefficient at the wall, Couple stress coefficient at the plate and the local surface heat flux are also thoroughly examined. Overall, this study sheds light on the complex interplay between physical parameters in the behavior of MHD micro-polar fluid past a porous medium in the presence of chemical reaction.

Rapid One-pot, Four Component Synthesis of Pyranopyrazoles Using Heteropolyacid Under Solvent-free Condition

  • Chavan, Hemant V.;Babar, Santosh B.;Hoval, Rahul U.;Bandgar, Babasaheb P.
    • Bulletin of the Korean Chemical Society
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    • 제32권11호
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    • pp.3963-3966
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    • 2011
  • A series of pyranopyrazoles, was efficiently synthesized via one-pot, four component reaction of ethyl acetoacetate, hydrazine hydrate, aldehydes and malononitrile in the presence of catalytic amount silicotungstic acid under solvent free condition. NOE experiments confirmed that the product exist exclusively in the 2H form. The present protocol offers the advantages of clean reaction, short reaction time, high yield, easy purification and economic availability of the catalyst.

표면 화학 반응이 드릴 가공에 미치는 영향 (The Effect to Drilling by The Chemical Reaction on The Surface)

  • 이현우;최재영;정상철;박준민;정해도;최헌종;이석우
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.976-979
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    • 2002
  • This research presents the new method to fabricate small features through applying chemical mechanical micro machining(C3M) for Al5052 and single crystal silicon. To improve machinability of ductile and brittle material, reacted layer was formed on the surface before micro-drilling process by chemical reaction with $HNO_3$(10wt%) and KOH(10wt%). And then workpieces were machined to compare conventional micro-drilling process with newly suggested one. To evaluate whether or not the machinability was improved by the effect of chemical condition, surface defects such as burr, chipping and crack generation were measured. Finally, it is confirmed that C3M is one of the feasible tools for micro machining with the aid of effect of the chemical reaction.

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Morita-Baylis-Hillman Route to Dimethyl 2,3-Dihydrobenzo[b]oxepine-2,4-dicarboxylates and Methyl 2-(2-Carbomethoxybenzo[b]furan-3-yl)propanoates from Salicylaldehydes

  • Ahn, Sang-Hyun;Jang, Seung-Soon;Kim, Young-Keun;Lee, Kee-Jung
    • Bulletin of the Korean Chemical Society
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    • 제33권1호
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    • pp.233-242
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    • 2012
  • A new synthetic method for dimethyl 2,3-dihydrobenzo[b]oxepine-2,4-dicarboxylates and methyl 2-(2-carbomethoxybenzo[b]furan-3-yl)propanoates by an intramolecular conjugate displacement reaction or an $S_N2$ reaction of acetates of Morita-Baylis-Hillman adducts of methyl (2-formylphenoxy)acetates has been described.

Miniaturization of Polymerase Chain Reaction

  • Lee, Ji-Youn;Kim, Jae-Jeong;Park, Tai-Hyun
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제8권4호
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    • pp.213-220
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    • 2003
  • Polymerase chain reaction (PCR) is one of the most widely used analytical tool and is an important module that would benefit from being miniaturized and integrated onto diagnostic or analytical chips. There are potentially two different approaches for the miniaturization of the PCR module: chamber-type and flow-type micro-PCR. These miniaturized PCRs have distinct characteristics and advantages. In this article, we review the necessity of micro-PCR, the materials for the chip fabrication, the surface modification, and characteristics of the two types of micro-PCR. The motivation underlying the development of micro-PCR, the advantages and disadvantages of the various materials used in fabrication and the surface modification methods will be discussed. And finally, the precise features of the two different types of micro-PCR will be compared.