The Experts below are selected from a list of 18189 Experts worldwide ranked by ideXlab platform
Bo B Iversen - One of the best experts on this subject based on the ideXlab platform.
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high temperature and high pressure aqueous solution formation growth crystal structure and magnetic properties of bifeo3 nanocrystals
Chemistry of Materials, 2011Co-Authors: Jianli Mi, Thomas N Jensen, Mogens Christensen, Christoffer Tyrsted, Jens Erik Jorgensen, Bo B IversenAbstract:In situ synchrotron radiation powder X-ray diffraction (SR-PXRD) was applied to study the formation and growth of BiFeO3 nanocrystals, revealing that phase pure BiFeO3 can be obtained in high-temperature, high-pressure aqueous solution using Bi(NO3)3 and Fe(NO3)3·9H2O as precursors and KOH as mineralizer. The method gives a rapid way for preparation of nanomaterials, and the formation of BiFeO3 can be finished within seconds after its initial nucleation in near-critical aqueous solution. As proof of concept BiFeO3 nanocrystals were subsequently synthesized in a continuous flow Supercritical System and for reference also in autoclaves. High resolution multitemperature SR-PXRD data were measured between 100 and 1000 K with a step size of 100 K. The magnetic properties of both the autoclave and the continuous flow samples are studied.
Zhou Huaichun - One of the best experts on this subject based on the ideXlab platform.
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development of a distributed parameter model for the evaporation System in a Supercritical w shaped boiler
Applied Thermal Engineering, 2014Co-Authors: Zheng Shu, Luo Zixue, Deng Yanxiang, Zhou HuaichunAbstract:Abstract In this paper, a distributed parameter model of an evaporation System in a Supercritical W-shaped once-through boiler is developed based on the 3-D temperature distribution. The mathematical model was formulated to predict the distributions of the heat flux and the metal-surface temperature while considering a non-uniform distribution of the surface heat transfer and the frictional resistance coefficient. The results show that the heat flux distribution on the front water wall has three high heat flux zones in the W-shaped boiler, and the peak of the heat transfer coefficient moves to the peak of the heat flux gradually with the increment of load at Supercritical pressure. The maximum deviation of the metal temperature is nearly 94 °C for different loads. This distributed parameter model is fit for the in-situ operating status of the boiler, and it provides a reference for the heat transfer of a Supercritical System.
Jianli Mi - One of the best experts on this subject based on the ideXlab platform.
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high temperature and high pressure aqueous solution formation growth crystal structure and magnetic properties of bifeo3 nanocrystals
Chemistry of Materials, 2011Co-Authors: Jianli Mi, Thomas N Jensen, Mogens Christensen, Christoffer Tyrsted, Jens Erik Jorgensen, Bo B IversenAbstract:In situ synchrotron radiation powder X-ray diffraction (SR-PXRD) was applied to study the formation and growth of BiFeO3 nanocrystals, revealing that phase pure BiFeO3 can be obtained in high-temperature, high-pressure aqueous solution using Bi(NO3)3 and Fe(NO3)3·9H2O as precursors and KOH as mineralizer. The method gives a rapid way for preparation of nanomaterials, and the formation of BiFeO3 can be finished within seconds after its initial nucleation in near-critical aqueous solution. As proof of concept BiFeO3 nanocrystals were subsequently synthesized in a continuous flow Supercritical System and for reference also in autoclaves. High resolution multitemperature SR-PXRD data were measured between 100 and 1000 K with a step size of 100 K. The magnetic properties of both the autoclave and the continuous flow samples are studied.
P. Whalen - One of the best experts on this subject based on the ideXlab platform.
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Monte-Carlo eigenvalue calculation
Monte-Carlo Methods and Applications in Neutronics Photonics and Statistical Physics, 1Co-Authors: D. Brockway, P. Soran, P. WhalenAbstract:A Monte Carlo algorithm to efficiently calculate static alpha eigenvalues, N = neαt, for Supercritical Systems has been developed and tested. A direct Monte Carlo approach to calculating a static alpha is to simply follow the buildup in time of neutrons in a Supercritical System and evaluate the logarithmic derivative of the neutron population with respect to time. This procedure is expensive, and the solution is very noisy and almost useless for a System near critical. The modified approach is to convert the time-dependent problem to a static α-eigenvalue problem and regress a on solutions of a k-eigenvalue problem. In practice, this procedure is much more efficient than the direct calcuation, and produces much more accurate results. Because the Monte Carlo codes are intrinsically three-dimensional and use elaborate continuous-energy cross sections, this technique is now used as a standard for evaluating other calculational techniques in odd geometries or with group cross sections.
Zheng Shu - One of the best experts on this subject based on the ideXlab platform.
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development of a distributed parameter model for the evaporation System in a Supercritical w shaped boiler
Applied Thermal Engineering, 2014Co-Authors: Zheng Shu, Luo Zixue, Deng Yanxiang, Zhou HuaichunAbstract:Abstract In this paper, a distributed parameter model of an evaporation System in a Supercritical W-shaped once-through boiler is developed based on the 3-D temperature distribution. The mathematical model was formulated to predict the distributions of the heat flux and the metal-surface temperature while considering a non-uniform distribution of the surface heat transfer and the frictional resistance coefficient. The results show that the heat flux distribution on the front water wall has three high heat flux zones in the W-shaped boiler, and the peak of the heat transfer coefficient moves to the peak of the heat flux gradually with the increment of load at Supercritical pressure. The maximum deviation of the metal temperature is nearly 94 °C for different loads. This distributed parameter model is fit for the in-situ operating status of the boiler, and it provides a reference for the heat transfer of a Supercritical System.