• Title/Summary/Keyword: Thermal Reaction

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Formation of Polychlorinated Dibenzo-p-Dioxins and Their Thermal Decomposition Products from Pyrolysis Reactions of Chlorophenates

  • Hong, Jongki;Park, Jongsei;Kim, Kang-Jin
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.821-827
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    • 1995
  • Polychlorodibenzo-p-dioxins(PCDDs) have been prepared by microsacale pyrolysis of trichlorophenates. During the pyrolysis reaction, dechlorinated dibenzo-p-dioxins were also formed by the thermolysis of PCDDs. The dechlorination pathways of PCDDs were suggested in this reaction. The identification of these products was performed using capillary column gas chromatography-mass spectrometry.

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Estimation of Adiabatic Temperature Rise of Concrete (콘크리트 단열온도 상승 예측에 관한 연구)

  • 방기성;정원섭;송영철;조철희
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10b
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    • pp.934-939
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    • 1998
  • This study discusses the results of adiabatic temperature rise tests which were performed considering various parameters, such as cement type, water-cement ratio, unit cement weigh, admixtures and placing temperature, which influence the temperature rise(K) and reaction velocity ($\alpha$). Theadiabatic temperature rise models obtained from this study are similar to those of Japan Concrete Institute. The models to calculate temperature rise and reaction velocity could be used the analysis f concrete thermal stress.

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Hydrophobic Catalyst Mixture for the Isotopic Exchange Reaction between Hydrogen and Water

  • Paek S.;Ahn D.H.;Choi H.J.;Kim K.R.;LEE M.;YIM S.P.;CHUNG H.
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.11b
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    • pp.141-148
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    • 2005
  • Pt/SDBC catalyst, which is used for the hydrogen-water isotopic exchange reaction, was prepared. The various properties of the catalyst, such as the thermal stability, pore structure and the platinum dispersion, were investigated. A hydrophobic Pt/SDBC catalyst which has been developed for the LPCE column of the WTRF (Wolsong Tritium Removal Facility) was tested in a trickle bed reactor. An experimental apparatus was built for the test of the catalyst at various temperatures and gas velocities.

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Cycloadditiona reaction of 5-(2-thienyl)methylene derivatives of thiazolidinone-4-thiones and their antimicrobial activities

  • Ead, Hamed A.;Metwalli, Nadia H.;Morsi, Nagwa M.
    • Archives of Pharmacal Research
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    • v.13 no.1
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    • pp.5-8
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    • 1990
  • The cycloaddition of the newely synthesized 5-(2-thienyl)methylene derivatives of thiazolidinone-4-thiones, 2a-c to acrylonitrile (3a), ethylacrylate (3b), N-phenylmaleimide (6) and dimethyl fumarate (8) has been evaluated. Under thermal reaction conditions [4 +2] cycloaddition proceeds with complete site and regioselectivity to yield the cycloadduct, 4, 5, 7 and 9, respectively. The antimicrobial activities of some of the new products were tested.

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Modeling and controller design for a continuous copolymerization reactor (연속식 공중합 반응기의 모델링 및 제어기 설계)

  • 황우현;이현구
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.788-791
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    • 1996
  • A mathematical model is developed for thermal solution copolymerization of styrene and acrylonitrile in a continuous stirred tank reactor(CSTR). Computational studies are carried out with the continuous copolymerization system model developed in this work to give the monomer conversion, copolymer composition and the average molecular weights of the copolymer. By performing the dynamic analysis of the reaction system, the polymer properties against the changes in the operating conditions are determined quantitatively. The cascade PID and fuzzy controller show satisfactory performances for both set point tracking and disturbance rejection. Especially, the fuzzy controller is superior to the PID controller.

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Preparation of Ultra Fine Alumina Powder Via Ammonium Aluminium Carbonate Hydroxide (AACH 를 이용한 고순도 알루미나 분말 제조)

  • Tun, Zhu;Shin, Kun-Chul
    • Journal of Industrial Technology
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    • v.24 no.B
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    • pp.65-71
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    • 2004
  • The ultra fine gamma-alumina powder was prepared via ammonium aluminium carbonate hydroxide (AACH). The XRD, SEM, BET, thermal analysis were used to characterize the samples. The effects of various reaction parameters as concentration, of solution, anion on specific area, PH, aging time and thermal decomposition condition on the produced AACH and alumina were discussed.

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Reaction of Lithium 2-Pyridyloxyalkylcuprates Having Improved Thermal Stability with Acid Chlorides and $\alpha,\beta$-Unsaturated Ketones

  • Lee, Phil-Ho;Shim, Sang-Chul;Kim, Sung-Gak
    • Bulletin of the Korean Chemical Society
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    • v.7 no.6
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    • pp.425-428
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    • 1986
  • A new heterocuprate containing 2-pyridyloxy ligand, lithium 2-pyridyloxy-n-butylcuprate, has shown improved thermal stability and it reacts with acid chlorides to afford the corresponding ketones in high yields. Similarly, it can be effectively utilized in conjugate addition reactions of $\alpha,\beta$-unsaturated ketones. Of synthetic significance is that the complete utilization of n-butyl group in lithium 2-pyridyloxy-n-butylcuprate has been observed.

An Investigation on Combustion Characteristics of Hydrogen-Air Premixture in a Sub-millimeter Scale Catalytic Combustor using Infrared Thermography (적외선 열화성 온도 측정법을 이용하여 살펴본 서브밀리미터 스케일 촉매 연소기에서의 수소-공기 예혼합 가스의 촉매 연소 특성)

  • Choi, Won-Young;Kwon, Se-Jin
    • Journal of the Korean Society of Combustion
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    • v.10 no.3
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    • pp.17-24
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    • 2005
  • A sub-millimeter scale catalytic combustor with a simple plate-shaped combustion chamber was fabricated. A porous ceramics support coated with platinum catalyst was placed in the chamber. The combustor has a gallium arsenide window on the top that is transparent to infrared ray. The temperature distribution in the combustion chamber was measured using infrared thermal imager while hydrogen-air premixture is steadily supplied to the combustor. The area where the catalytic reaction took place broaden for higher flow rate and lower equivalence ratio made activated area in the combustion chamber broaden. The amount of coated platinum catalyst did not affect the reaction. Stop of reaction, which is similar to flame quenching of conventional combustion, was investigated. Large content of heat generation and broad activated area are essential criteria to prevent stop of reaction that has a bad effect on the combustor performance.

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Synthesis of Organo-montmorillonite by Intercalation Reaction and its Kinetic Study (Intercalation 반응에 의한 Organo-montmorillonite의 합성 및 반응속도 연구)

  • 김창은;최진호;형경우
    • Journal of the Korean Ceramic Society
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    • v.21 no.1
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    • pp.67-73
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    • 1984
  • A stable intercalation complex was formed by adsorption of alcanol (ROH, R; $C_{10}H_2$, $C_{12}H_{25}$, $C_{14}H_{29}$) on the surfaces of Yongil bentonite in which the interlayer cation had been exchanged by n-decylammonium ion $(C_{10}H_{21}NH_3^+)$ The layer charge density calculated from the increaments of basal spacings was 0.34 per unit chemical formula. Thermochemical properties of synthesized $C_{10}H_{21}NH_3^+$ montmorillonite were studied by means of DSC, TGA, DTG, Thermal analysis showed two steps of desoption behavior of $C_{10}H_{21}NH_3^+$ ion namely nonyl $(CH_3(CH_2)_8$ decomposition reaction of 40$0^{\circ}C$ and methyleneammonium decomposition reaction of 78$0^{\circ}C$ The activation energy of nonyl decomposition reaction of $C_{10}H_{21}NH_3^+$ -montmorillonite respectively.

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