• Title, Summary, Keyword: Decomposition behavior

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Distortional Analysis of Multicell Box Girders with a Trapezoidal Cross-Section Using Force-Decomposition Method (하중분해법을 사용한 제형 다실박스거더의 뒤틀림 해석)

  • Kim, Seungjun;Park, Nam Hoi;Kang, Young Jong
    • Journal of The Korean Society of Civil Engineers
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    • v.28 no.6A
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    • pp.779-788
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    • 2008
  • In this present study, the three dimensional shell elements analysis method for exact distortional behavior of multicell trapezoidal box girders subjected to an eccentric loading is proposed. In order to perform the independent distortional analysis using shell elements, it is necessary to calculate exact distortional forces. In this study, the force-decomposition equation for applied eccentric load acting on multicell trapezoidal box girder is derived and the equation based on static force equilibrium and superposition theory decompose the eccentric load to the loads cause flexture, torsion and distortion. So by using this force-decomposition equation and shell element analysis, each behavior can be easily analysis independently. This independent analysis method is very useful to physically understand each major behavior of multicell box girder, especially distortional phenomenon. Furthermore, it may be also very useful for designer to perform the independent distortional analysis for diaphragm design using simple 3D shell elements model without preliminary complex calculation for distortional constants.

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Behavior and Decomposition Velocity of Pollutants on Various Forms from Domestic Sewage in Small-scale Sewage Treatment Plant by Natural Purification Method (자연정화공법에 의한 농촌 전원독립가구 하수처리장에서 하수 중 오염물질의 존재형태별 거동과 분해속도)

  • Seo, Dong-Cheol;Kim, Hyung-Jun;Park, Woo-Young;Lim, Jong-Sir;Hwang, Seung-Ha;Park, Chan-Hoon;Choi, Jeong-Hwan;Lee, Hong-Jae;Lee, Do-Jin;Cho, Ju-Sik;Heo, Jong-Soo
    • Korean Journal of Environmental Agriculture
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    • v.27 no.1
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    • pp.18-26
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    • 2008
  • Behavior and decomposition velocity of pollutants on various forms from domestic sewage in sewage treatment plant were investigated in order to obtain the basic data for improving the removal efficiency of pollutants and to reduce the area in constructed wetland by natural purification method. The removal amounts of BODs and CODs in aerobic bed were significantly higher than those of the other beds. In aerobic bed, the removal amounts of IBOD and ICOD were more than those for SBOD and SCOD, respectively, whereas the removal amounts of BODs and CODs in anoxic and anaerobic beds were little different. The removal amounts of SSs in aerobic bed were also higher than those for the other beds, and the removal amounts of VSS in all beds were more than those for FSS. The removal amounts of DTN and DTP in all beds were more than those for STN and STP, respectively. In addition, the decomposition velocities of TBOD, TCOD and TSS in aerobic bed were 30.79, 17.15 and 29.96 $day^{-1}$. Moreover, the decomposition velocities of BODs, CODs and SSs in aerobic bed were very rapid than those in the other beds. On the other hand, the decomposition velocities of BODs, CODs and SSs in anoxic and anaerobic beds were a little different regardless of the forms of pollutant. The decomposition velocities constants of T-N in aerobic, anoxic and anaerobic beds were 4.78, 0.12 and 0.10 $day^{-1}$, respectively. Moreover, the decomposition velocities constants of T-P in aerobic, anoxic and anaerobic beds were 13.09, 0.12 and 0.13 $day^{-1}$ respectively. The decomposition velocity of T-Ns and T-Ps in aerobic bed were slightly rapid than those in the other beds, whereas the decomposition velocities of T-Ns and T-Ps in anoxic and anaerobic beds were slightly different regardless of the forms of pollutant.

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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Thermal Decomposition Activation Energy according to the Mesogen Structure of Liquid Crystalline Epoxy Composite with Aluminum Oxide Filler (산화 알루미늄을 분산시킨 열경화성 액정 에폭시의 Mesogen 구조에 따른 열분해 활성화 에너지)

  • Hyun, Ha Neul;Cho, Seung Hyun
    • Textile Science and Engineering
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    • v.56 no.5
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    • pp.314-320
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    • 2019
  • A liquid crystalline thermosetting-epoxy-based composite was fabricated using diglycidyl ether of 4,4'-bisphenol and diglycidyl ether of terephthalylidene-bis-(4-amino-3-methylphenol), with aluminum oxide as a filler, and sulfanilamide and 4,4'-diaminodiphenylethane as a curing agent. Thermogravimetric analysis was performed to investigate its thermal behavior, and temperature differences of the sample were recorded using 1.0-7.0 wt% aluminum oxide. The activation energy for thermal decomposition was calculated using the Kissinger method, and the Flynn-Wall method. The results showed that the activation energy was proportional to the amount of filler added.

Nonlinear Analysis of RC Slabs based on the Strain Decomposition Technique (변형률 분할기법을 이용한 철근콘크리트 슬래브의 비선형 유한요소해석)

  • Chung Won-Seok;Woo Young-Jin
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.433-439
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    • 2005
  • This paper describes a reinforced concrete crack model, which utilizes a strain decomposition technique. The strain decomposition technique enables the explicit inclusion of physical behavior across the cracked concrete surface such as aggregate interlock and dowel action rather than intuitively defining the shear retention factor. The proposed concrete crack model is integrated into the commercial finite element software ABAQUS shell elements through a user-supplied material subroutine. The FE results have been compared to experimental results reported by other researchers. The proposed bridge FE model is capable of predicting the initial cracking load level, the ultimate load capacity, and the crack pattern with good accuracy.

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Analysis of Breakdown Voltage Dispersion and Breakdown Process in Mineral Oil (광유 중 절연파괴전압의 분산과 절연파괴진전 과정의 분석)

  • Lim, Dong-Young;Park, Sung-Gyu;Park, Cheol-Ho;Kim, Ki-Chai;Lee, Kwang-Sik;Choi, Eun-Hyeok
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.6
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    • pp.35-41
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    • 2015
  • This paper presents a breakdown voltage and a process of breakdown progress in mineral oil under an quasi-uniform field with decomposition products which occur after the oil discharge. The breakdown voltage in the oil revealed the characteristics of dispersion regardless of an electrode gap. The cumulative probability distribution was used to analyze the dispersion of the breakdown voltage. In addition, the process of breakdown progress in the oil can be reasonably described by the electron breakdown theory based on both electrons emitted from the cathode and ions by field-aided dissociation of the oil. The proposed breakdown process will be used for the basic data to explain the behavior pattern of the decomposition product to cause the dispersion of the breakdown voltage.

Preparations of Nano-scale Mullite Powder from Solution Combustion Synthesis (용액연소합성에 의한 나노크기 물라이트 분말의 제조)

  • Lee, Sang-Jin;Yun, Jon-Do;Gwon, Hyeok-Bo;Jeon, Byeong-Se
    • Korean Journal of Materials Research
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    • v.11 no.9
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    • pp.797-801
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    • 2001
  • In this study, the solution combustion method was employed to synthesize stoichiometric mullite, and hence the attrition process was employed to prepare ultrafine mullite particles with nano size. The thermal decomposition behavior and partial pressure of equilibrium species of both oxidizer and fuel were considered during solution combustion process. The synthesized product was mullite phase with 40 nm crystalline size, and the alumina contents of the product by TEM/EDS quantity analysis was 3.12$\pm$04 mole. The result showed that the synthesized mullite was almost close to the it's stoichiometric composition. For attrition process, the dispersion behavior of the mullite suspension was controlled and was comminuted with the condition of 800 rpm for 4 hours using 0.3 mm zirconia ball media. As a result of comminution, the mean particle size was 80 nm.

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