• 제목/요약/키워드: Thermogravimetric Analysis

검색결과 803건 처리시간 0.024초

Pilot 규모의 열분해 용융 소각 시스템에서의 열분해 및 연소 특성 연구 (A Study on the Pyrolysis and Combustion Characteristics of Solid Waste in a Pilot scale Pyrolysis Melting Incinerator)

  • 류태우;양원;박주원;김봉근;이기방;김희열;박상신;전금하
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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    • pp.168-174
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    • 2006
  • A pilot scale (200kg/hr) pyrolysis melting incineration system is designed and constructed in Korea Institute of Industrial Technology. The incineration process is composed of pyrolysis, gas combustion, ash melting, gas stabilization, waste heating boiler, and bag filter. For each unit process, experimental approaches have been conducted to find optimal design and operating conditions. Especially, a pyrolysis is very important process in that it is a way of energy recirculation and minimizing the waste products. This paper presents major results of the most efficient operating conditions in a pilot scale pyrolysis melting incinerator.

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발사르탄 이칼륨염의 신규 결정형 (New Crystal form of Valsartan Dipotassium Salt)

  • 서성기;김대덕;오의철
    • Journal of Pharmaceutical Investigation
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    • 제39권3호
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    • pp.173-176
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    • 2009
  • A new crystal form of valsartan dipotassium was isolated by recrystallization using the one-pot method. The new crystal form was identified as a monohydrate form ($C_{24}H_{27}N_5O_3K_2.H_2O$) and characterized by diffential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray powder diffractometry (PXRD). The new crystal data demonstrated to be clearly different from those known for the tetrahydrate form ($C_{24}H_{27}N_5O_3K_2.4H_2O$). It was observed that the monohydrate of vasartan dipotassium salt was completely dissolved in water within 1 hour and its dissolution rate was much faster than anhydrous free form of valsartan.

자외선 조사를 이용한 PEO 필름의 광가교 (Photocrosslinking of PEO Films Using UV Irradiation)

  • 구광회;장진호
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2008년도 제38차 학술발표대회
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    • pp.28-30
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    • 2008
  • Poly(ethylene oxide)(PEO) of molecular weight of 300,000 was crosslinked by exposure to UV irradiation. Photochemical crosslinking of PEO occurred by UV irradiation and the presence of benzophenone in the film which acts as a hydrogen-abstracting agent. Percent conversion of the polymer into gel as well as water absorbency were investigated gravimetrically. Gel fraction and water absorbency of PEO films increased with increasing UV energy. In case of photocrosslinked PEO films with benzophenone, gel fraction increased up to about 90%. The thermal behavior of crosslinked PEO films was studied by thermogravimetric analysis. The maximum decomposition temperature increased with increasing UV energy and benzophenone concentration.

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Oxidative Coupling Polymerization of Diethynylsilane Derivatives and 1,2-Diethynyl-1,1,2,2-tetramethyldisilane

  • Kim, Ji-Ho;Park, Young-Tae
    • Bulletin of the Korean Chemical Society
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    • 제27권6호
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    • pp.869-874
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    • 2006
  • We have carried out the Glaser oxidative coupling polymerizations of diethynyldiphenylsilane, diethynylmethylphenylsilane,diethynylmethyloctylsilane, and 1,2-diethynyl-1,1,2,2-tetramethyldisilane to afford polycarbosilanes containing diethynyl and organosilane groups in the main chain, such as poly(diethynyldiphenylsilane), poly(diethynylmethylphenylsilane), poly(diethynylmethyloctylsilane), and poly(1,2-diethynyl-1,1,2,2-tetramethyldisilane), respectively. These obtained materials are almost insoluble in common organic solvents such as $CHCl_3$ and THF probably due to the presence of a rigid rod diacetylene group along the polymer main chain. Therefore, the polymers were characterized using several spectroscopic methods in solid state. FTIR spectra of all the polymeric materials show that the characteristic $C \equiv C$ stretching frequencies appear at 2147-2154 $cm ^{-1}$, in particular. The polymers in the solid state exhibit that the strong maximum excitation peaks appear at 260-283 nm and the strong maximum fluorescence emission bands at 367-412 nm, especially. Thermogravimetric analysis of the materials shows that about 55-68% of the initial polymer weights remain at 400 ${^{\circ}C}$ in nitrogen.

Analysis of the Microstructure and Oxidation Behavior of Some Commercial Carbon Fibers

  • Kim, Dae-Ho;Kim, Bo-Hye;Yang, Kap-Seung;Bang, Yun-Hyuk;Kim, Sung-Ryong;Im, Hun-Kook
    • 대한화학회지
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    • 제55권5호
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    • pp.819-823
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    • 2011
  • The relationship between the microstructure, mechanical properties, and oxidation behavior of pitch-, polyacrylonitrile (PAN)-, and Rayon-based carbon fibers (CFs) has been studied in detail. Three types of carbon fiber were exposed to isothermal oxidation in air and the weight change was measured by thermogravimetric analyzer (TGA) apparatus. After activation energy was gained according to the conversion at reacting temperature, the value of specific surface area and the surface morphology was compared, and the reaction mechanism of oxidation affecting development of pores of carbon fibers was examined. This study will lead to a new insight into the relationship between the microstructure and mechanical properties of carbon fibers.

A modified electrode by a facile green preparation of reduced graphene oxide utilizing olive leaves extract

  • Baioun, Abeer;Kellawi, Hassan;Falah, Ahamed
    • Carbon letters
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    • 제24권
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    • pp.47-54
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    • 2017
  • Different phytochemicals obtained from various natural plant sources are used as reduction agents for preparing gold, copper, silver and platinum nanoparticles. In this work a green method of reducing graphene oxide (rGO) by an inexpensive, effective and scalable method using olive leaf aqueous extract as the reducing agent, was used to produce rGO. Both GO and rGO were prepared and investigated by ultraviolet and visible spectroscopy, Fourier-transform infrared, scanning electron microscopy, atomic force microscopy, thermogravimetric analysis, cyclic voltammetry, X-ray photoelectron spectra, electrochemical impedance spectroscopy and powder X-ray diffraction.

Preparation and characterization of nanosized hollow silica in the presence of aluminum isopropoxide

  • Nguyen, Ngoc Anh Thu;Kim, Hyun-Ik;Kim, Sang Hern
    • 한국응용과학기술학회지
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    • 제33권3호
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    • pp.421-427
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    • 2016
  • Nanosized hollow silica was prepared by $St{\ddot{o}}ber$ method in the presence of aluminum isopropoxide. The mixture of polyelectrolytes such as poly(sodium 4-styrene sulfonate)(PSS) and polyacrylic acid(PAA) were used as templates. Tetraethylorthosilicate(TEOS) and aluminum isopropoxide were used as precursors for silica and alumina, respectively. The function of aluminum isopropoxide is to increase the porosity of silica shell. The characterizations of hollow silica were examined by TEM(transmission electron microscopy), TGA(thermogravimetric analysis), BET(Brunauer Emmett Teller), Energy-dispersive X-ray spectroscopy(EDS), and FT-IR spectrum. It was found that the shell thickness of hollow silica was around 8 nm and the core diameter was around 20 nm by TEM.

Preparation and Characterization of Carbonized Material from Al-Fe-Mg-Si Nanocomposites Impregnated Biomass

  • Kim, Jin Woo;Lee, Chul Jae
    • International Journal of Advanced Culture Technology
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    • 제6권2호
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    • pp.129-136
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    • 2018
  • Our present study, we impregnated Al-Fe-Mg-Si (NFM) nanocomposites having various concentrations 0, 1000, 3000, and 5000 mg/L in biomass in order to make carbonized biomass. We characterized the properties of the impregnated samples through thermogravimetric/differential thermal analysis (TG-DTA), pore distribution, scanning electron microscopy (SEM). The best results were observed for a NFM nanocomposites concentration of 5000 mg/L. After the first heat treatment, carbonization, and activation processes, the fixed carbon ratio and iodine adsorptivity were increased by 21.89% and 368 mg/g, 23.98% and 475 mg/g, 26.40% and 238 mg/g, respectively. The remove rate of malodorous and VOCs were that the sample shows good removal capabilities. From above results, our sample could be used for the removal of noxious and malodorous gases and for the purification of wastewater.

A Facile Approach to Fabrication of Hollow ZnO Nanoparticles

  • Cho, Gwang-Rae;Kim, Dong-Hyeon;Lee, Dong-Hoon
    • Composites Research
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    • 제31권3호
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    • pp.94-98
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    • 2018
  • Well-defined, monodispersed hollow ZnO nanoparticles were successfully synthesized by a facile one-pot solution method at room temperature. Hollow ZnO nanoparticles were fabricated using polystyrene nanoparticles as seed particles. The removal of core particles via solvent extraction yields hollow nanoparticles. The structures and morphologies of the obtained products were characterized with Fourier transform infrared (FT-IR), Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction pattern (XRD) and Scanning electron microscopy (SEM). The formation mechanism of the hollow structure of the ZnO nanoparticles was also investigated. The technique developed here is expected to be useful in the preparation other metal oxides and hollow architectures.

알카리토금속 화합물에 의한 루테늄의 흡착 (Adsorption of Ruthenium on the alkaline Earth Metal Compounds)

  • 류경옥;문세기;이근범
    • 한국세라믹학회지
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    • 제19권2호
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    • pp.145-151
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    • 1982
  • Many materials such as silica gel, metallic oxide, activated alumina and alkaline earth metal carbonates were employed as filter media for gaseous oxides of ruthenium volatilized during high level radioactive waste processing. The adsorption efficiency of ruthenium on these materials was evaluated. For the purpose of observing behavior of ruthenium oxides, thermogravimetric analysis of ruthenium oxide in a stream of oxygen was carried out. The rate of volatilization was proportional to the square root of oxygen partial pressure, and increased exponentially with temperature. At $650^{\circ}C$, gaseous ruthenium oxides showed a strongly marked effect of deposition. Of all the materials available, calcium oxide proved to be the best that could be used to adsorb ruthenium.

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