The Experts below are selected from a list of 108129 Experts worldwide ranked by ideXlab platform
R. W. Henning - One of the best experts on this subject based on the ideXlab platform.
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maximum Entropy Method analysis of thermal motion and disorder in thermoelectric clathrate ba8ga16si30
Journal of Applied Physics, 2002Co-Authors: Anders Bentien, Bo B. Iversen, J. D. Bryan, Galen D. Stucky, A. E. C. Palmquist, Arthur J. Schultz, R. W. HenningAbstract:Multitemperature (15, 100, 150, 200, 300, 450, 600, 900 K) single crystal neutron diffraction data on the type I clathrate Ba8Ga16Si30 are reported. For the framework atoms reciprocal space structural refinements give total occupancies in the unit cell of Ga/Si=3.8/2.2, 1.8/14.2, 10.2/13.8 for the 6c, 16i, and 24k sites respectively, thus showing that Ga avoids the tetrahedral 16i positions. The guest atom displacement parameters obtained from structure factor fitting are analyzed with semianharmonic Einstein models giving Einstein temperatures (ΘE) of 69(1), 98(7), and 124(2) K for Ba(2)(100), Ba(2)[100], and Ba(1), respectively. The analysis furthermore suggests that all guest atoms are structurally disordered, and the disorder appears to be temperature dependent with increased host-guest interaction at high temperatures. The structure factors are subsequently used in the maximum Entropy Method calculations to obtain direct space nuclear densities. These are modeled with anharmonic one-particle potential models to fourth order. Even at elevated temperatures anharmonicity is limited indicating that the low thermal conductivity of the clathrate has a different origin.
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Maximum Entropy Method analysis of thermal motion and disorder in thermoelectric clathrate Ba8Ga16Si30
Journal of Applied Physics, 2002Co-Authors: Anders Bentien, Bo B. Iversen, J. D. Bryan, Galen D. Stucky, A. E. C. Palmquist, Arthur J. Schultz, R. W. HenningAbstract:Multitemperature (15, 100, 150, 200, 300, 450, 600, 900 K) single crystal neutron diffraction data on the type I clathrate Ba8Ga16Si30 are reported. For the framework atoms reciprocal space structural refinements give total occupancies in the unit cell of Ga/Si=3.8/2.2, 1.8/14.2, 10.2/13.8 for the 6c, 16i, and 24k sites respectively, thus showing that Ga avoids the tetrahedral 16i positions. The guest atom displacement parameters obtained from structure factor fitting are analyzed with semianharmonic Einstein models giving Einstein temperatures (ΘE) of 69(1), 98(7), and 124(2) K for Ba(2)(100), Ba(2)[100], and Ba(1), respectively. The analysis furthermore suggests that all guest atoms are structurally disordered, and the disorder appears to be temperature dependent with increased host-guest interaction at high temperatures. The structure factors are subsequently used in the maximum Entropy Method calculations to obtain direct space nuclear densities. These are modeled with anharmonic one-particle potentia...
Armando Leite M Da Silva - One of the best experts on this subject based on the ideXlab platform.
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risk assessment in probabilistic load flow via monte carlo simulation and cross Entropy Method
IEEE Transactions on Power Systems, 2019Co-Authors: Armando Leite M Da Silva, Andre Milhorance De CastroAbstract:In planning and operation of electric power systems, it is essential to perform several evaluations using the power flow algorithm to estimate and manage the operating point of the network being studied. The probabilistic load flow (PLF) algorithm aims to overcome the limitations imposed by the use of the conventional deterministic tool, allowing the consideration of input uncertainties. This paper proposes a new Method for calculating risk indices (e.g., probability of overloads in transmission equipment), based on Monte Carlo simulation (MCS) using importance sampling techniques via the cross-Entropy Method. In fact, the probability associated with any target region of the output PLF variables can be precisely evaluated. The flexibility and accuracy of the conventional MCS are maintained, while the computational time required is greatly reduced. The proposed Method is applied to different IEEE test systems and the obtained results are widely discussed.
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probabilistic assessment of spinning reserve via cross Entropy Method considering renewable sources and transmission restrictions
IEEE Transactions on Power Systems, 2018Co-Authors: Armando Leite M Da Silva, Jose Costa F Castro, R BillintonAbstract:This work presents a new Method to evaluate generation reserve margins in systems with renewable sources. In assessing the adequacy of generation reserve amounts, besides failures in generating units, their capacity intermittencies, unavailability, and capacity limits of the transmission system are duly considered. Risk indices are evaluated using quasi-sequential Monte Carlo simulation techniques. The cross-Entropy Method is used to treat rare events and also to identify critical equipment for operation in each scenario. The proposed Method is applied to the original IEEE RTS system and to a modified configuration with insertion of wind power plants. A subsystem of the Brazilian interconnected network is also used to illustrate the practicality of the proposed Method.
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spinning reserve assessment under transmission constraints based on cross Entropy Method
IEEE Transactions on Power Systems, 2016Co-Authors: Armando Leite M Da Silva, Jose Costa F Castro, Reinaldo A GonzalezfernandezAbstract:This paper proposes a Methodology to evaluate the spinning reserve requirements of generating systems, taking into consideration the loss of load risk due to failures in the generation and transmission network. In order to provide a more flexible and robust tool to assess the risk indices for bulk power systems, a Monte Carlo simulation based tool is proposed. Due to the rarity of the events associated with this particular problem, an unbiased estimator based on importance sampling is applied, and the set of optimal parameters is obtained using a cross-Entropy Method. The proposed Methodology is capable of assessing the operating reserve requirements, especially the one that is synchronized, to cope with failures and capacity restrictions of both generating and transmission systems. The IEEE-RTS (reliability test system) is used to test the proposed Methodology and also some modifications of this system are created to fully verify the ability of the proposed approach to satisfactorily respond to the transmission constraints.
Anders Bentien - One of the best experts on this subject based on the ideXlab platform.
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maximum Entropy Method analysis of thermal motion and disorder in thermoelectric clathrate ba8ga16si30
Journal of Applied Physics, 2002Co-Authors: Anders Bentien, Bo B. Iversen, J. D. Bryan, Galen D. Stucky, A. E. C. Palmquist, Arthur J. Schultz, R. W. HenningAbstract:Multitemperature (15, 100, 150, 200, 300, 450, 600, 900 K) single crystal neutron diffraction data on the type I clathrate Ba8Ga16Si30 are reported. For the framework atoms reciprocal space structural refinements give total occupancies in the unit cell of Ga/Si=3.8/2.2, 1.8/14.2, 10.2/13.8 for the 6c, 16i, and 24k sites respectively, thus showing that Ga avoids the tetrahedral 16i positions. The guest atom displacement parameters obtained from structure factor fitting are analyzed with semianharmonic Einstein models giving Einstein temperatures (ΘE) of 69(1), 98(7), and 124(2) K for Ba(2)(100), Ba(2)[100], and Ba(1), respectively. The analysis furthermore suggests that all guest atoms are structurally disordered, and the disorder appears to be temperature dependent with increased host-guest interaction at high temperatures. The structure factors are subsequently used in the maximum Entropy Method calculations to obtain direct space nuclear densities. These are modeled with anharmonic one-particle potential models to fourth order. Even at elevated temperatures anharmonicity is limited indicating that the low thermal conductivity of the clathrate has a different origin.
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Maximum Entropy Method analysis of thermal motion and disorder in thermoelectric clathrate Ba8Ga16Si30
Journal of Applied Physics, 2002Co-Authors: Anders Bentien, Bo B. Iversen, J. D. Bryan, Galen D. Stucky, A. E. C. Palmquist, Arthur J. Schultz, R. W. HenningAbstract:Multitemperature (15, 100, 150, 200, 300, 450, 600, 900 K) single crystal neutron diffraction data on the type I clathrate Ba8Ga16Si30 are reported. For the framework atoms reciprocal space structural refinements give total occupancies in the unit cell of Ga/Si=3.8/2.2, 1.8/14.2, 10.2/13.8 for the 6c, 16i, and 24k sites respectively, thus showing that Ga avoids the tetrahedral 16i positions. The guest atom displacement parameters obtained from structure factor fitting are analyzed with semianharmonic Einstein models giving Einstein temperatures (ΘE) of 69(1), 98(7), and 124(2) K for Ba(2)(100), Ba(2)[100], and Ba(1), respectively. The analysis furthermore suggests that all guest atoms are structurally disordered, and the disorder appears to be temperature dependent with increased host-guest interaction at high temperatures. The structure factors are subsequently used in the maximum Entropy Method calculations to obtain direct space nuclear densities. These are modeled with anharmonic one-particle potentia...
Jingnan Sun - One of the best experts on this subject based on the ideXlab platform.
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Entropy Method for determination of weight of evaluating indicators in fuzzy synthetic evaluation for water quality assessment
Journal of Environmental Sciences-china, 2006Co-Authors: Zhihong Zou, Yi Yun, Jingnan SunAbstract:Considering the difficulty of fuzzy synthetic evaluation Method in calculation of the multiple factors and ignorance of the relationship among evaluating objects, a new weight evaluation process using Entropy Method was introduced. This improved Method for determination of weight of the evaluating indicators was applied in water quality assessment of the Three Gorges reservoir area. The results showed that this Method was favorable for fuzzy synthetic evaluation when there were more than one evaluating objects. One calculation was enough for calculating every monitoring point. Compared with the original evaluation Method, the Method predigested the fuzzy synthetic evaluation process greatly and the evaluation results are more reasonable.
Bo B. Iversen - One of the best experts on this subject based on the ideXlab platform.
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maximum Entropy Method analysis of thermal motion and disorder in thermoelectric clathrate ba8ga16si30
Journal of Applied Physics, 2002Co-Authors: Anders Bentien, Bo B. Iversen, J. D. Bryan, Galen D. Stucky, A. E. C. Palmquist, Arthur J. Schultz, R. W. HenningAbstract:Multitemperature (15, 100, 150, 200, 300, 450, 600, 900 K) single crystal neutron diffraction data on the type I clathrate Ba8Ga16Si30 are reported. For the framework atoms reciprocal space structural refinements give total occupancies in the unit cell of Ga/Si=3.8/2.2, 1.8/14.2, 10.2/13.8 for the 6c, 16i, and 24k sites respectively, thus showing that Ga avoids the tetrahedral 16i positions. The guest atom displacement parameters obtained from structure factor fitting are analyzed with semianharmonic Einstein models giving Einstein temperatures (ΘE) of 69(1), 98(7), and 124(2) K for Ba(2)(100), Ba(2)[100], and Ba(1), respectively. The analysis furthermore suggests that all guest atoms are structurally disordered, and the disorder appears to be temperature dependent with increased host-guest interaction at high temperatures. The structure factors are subsequently used in the maximum Entropy Method calculations to obtain direct space nuclear densities. These are modeled with anharmonic one-particle potential models to fourth order. Even at elevated temperatures anharmonicity is limited indicating that the low thermal conductivity of the clathrate has a different origin.
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Maximum Entropy Method analysis of thermal motion and disorder in thermoelectric clathrate Ba8Ga16Si30
Journal of Applied Physics, 2002Co-Authors: Anders Bentien, Bo B. Iversen, J. D. Bryan, Galen D. Stucky, A. E. C. Palmquist, Arthur J. Schultz, R. W. HenningAbstract:Multitemperature (15, 100, 150, 200, 300, 450, 600, 900 K) single crystal neutron diffraction data on the type I clathrate Ba8Ga16Si30 are reported. For the framework atoms reciprocal space structural refinements give total occupancies in the unit cell of Ga/Si=3.8/2.2, 1.8/14.2, 10.2/13.8 for the 6c, 16i, and 24k sites respectively, thus showing that Ga avoids the tetrahedral 16i positions. The guest atom displacement parameters obtained from structure factor fitting are analyzed with semianharmonic Einstein models giving Einstein temperatures (ΘE) of 69(1), 98(7), and 124(2) K for Ba(2)(100), Ba(2)[100], and Ba(1), respectively. The analysis furthermore suggests that all guest atoms are structurally disordered, and the disorder appears to be temperature dependent with increased host-guest interaction at high temperatures. The structure factors are subsequently used in the maximum Entropy Method calculations to obtain direct space nuclear densities. These are modeled with anharmonic one-particle potentia...