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01878 Mass spectrometric studies on irradiated (U, Pu) mixed carbide fuel of FBTR
14 Fuel science and technology (fundamental science, analysis, instrumentation) tube diameter. For all fin pitches, the heat transfer coefficient decreased as the number of tube row increased from 1 to 4. The staggered tube alignment improved heat transfer performance more than 10% compared to the inline tube alignment. A heat transfer correlation was developed from the measured data for flat plate finnedtubes with large fin pitch. The correlation yielded good predictions of the measured data with mean deviations of 3.8 and 6.2% for the inline and staggered tube alignment, respectively.
06•01875 Hybrid algorithm based on EP and LP for security constrained economic dispatch problem Somasundaram, P. et al. Electric Power Systems Research, 2005, 76, (13), 77-85. This paper presents a new hybrid method for solving security constrained economic dispatch problem. The proposed method is developed in such a way that a simple evolutionary programming is applied as a base level search, which can give a good direction to the optimal global region and a local search linear programming is used as a fine tuning to determine the optimal solution. The hybrid approach outperforms the evolutionary programming based method and reduces the total computation time. A 10-bus and 66-bus Indian utility systems are considered to illustrate the effectiveness of the proposed method. The investigations reveal that the proposed method is suitable for practical utility systems.
06/01876 Isotope correlations for determining the isotopic composition of plutonium produced in research and power reactors using the experimental data obtained by alpha and mass spectrometry Aggarwal, S. K. and Alamelu, D. International Journal of Nuclear Energy Science and Technology, 2005, 1. (2-3), 215-219. Correlations have been developed for obtaining the isotopic composition of Pu produced in Indian research (CIRUS, D H R U V A ) and power (PHWR) reactors. The experimental data obtained on 238pu/ (239pu + 24°pU) a!pha activity ratio using alpha spectrometry and on 240 Pu/-n39 Pu, 241 Pu/" 39 Pu, 242 Pu/2 39 Pu atom ratios by thermal inoization mass spectrometry were used for developing isotope correlations.
06101877 Low-bandwidth open-loop control of combustion instability Uhm, J. H. and Acharya, S. Combustion and Flame, 2005, 142, (4), 348 363. A new strategy for open-loop control of combustion oscillations using a high-momentum air jet modulated at low frequencies is described. The oscillations in the swirl-stabilized spray combustor of interest are dominated by a longitudinal acoustic mode (235 Hz) with a lowfrequency (13 Hz) bulk mode (of the upstream cavity) superimposed. An effective strategy for control is demonstrated to be achieved through employment of a new concept that uses low-bandwidth, openloop modulation of a high-momentum air jet that penetrates directly into the region of strong combustion dynamics. It is shown that with low-frequency modulation (1-7 Hz) of the high-momentum air jet, the pressure oscillations can be reduced significantly (by a factor of nearly 10). Square-wave modulation is demonstrated to be considerably more effective than sine-wave modulation. These results are extremely promising as high-bandwidth actuation is not required for effective control.
06/01878 Mass spectrometric studies on irradiated (U, Pu) mixed carbide fuel of FBTR Balasubramanian, R, et al. International Journal of Nuclear Energy Science and Technology, 2005, 1, (2-3), 197-203. Mass spectrometry was employed to characterise the irradiated mixed carbide fuel of fast breeder test reactor (FBTR) for assessing its performance: thermal ionization mass spectrometry to determine the isotopic composition, concentrations of U, Pu and Nd in the dissolver solutions and to deduce the burn-up, and a quadrupole mass spectrometric system to obtain the percentage release of fission gases (Kr + Xe). A summary and analysis of the results obtained with the fuel at 25,000 and 50,000 MWd/t in these studies is given in this paper.
06•01879 Multi-component mathematical model of solid oxide fuel cell anode Hussain, M. M. et al. International Journal of Energy Research, 2005, 29, (12), 1083-1101. A mathematical model describing the multi-component species transport inside the porous solid oxide fuel cell (SOFC) anode has been developed. The model includes the water-gas shift reaction in the anode electrode (backing) layer and the spatially resolved electrochemical reaction in the reaction zone layer. The modified StefanMaxwell equations incorporating Knudsen diffusion were used to model multi-component diffusion inside the porous electrode (backing) and reaction zone layers. Moreover, the general Butler-Volmer equation was used to model the electrochemical reaction in the reaction zone layer. The model can predict the distribution of species
284
Fuel and Energy Abstracts
July 2006
within the SOFC anode for any reformate gas composition involving carbon dioxide, carbon monoxide, hydrogen and water vapour. The chemical and electrochemical reactions as well as transport processes in the SOFC anode can be simulated, yielding the anode performance under various operating and design conditions. This anode model can be coupled with a similarly developed model for the cathode to form an overall model for a single SOFC model,
06/01880 Numerical simulation of fuel droplet extinction due to forced convection Pope, D. N. and Gogos, G. Combustion andFlame, 2005, 142, (1-2), 89 106. The extinction of an envelope flame at the forward stagnation point of a liquid fuel droplet due to forced convection is numerically investigated. The droplet is oxidizing within an air stream at atmospheric pressure. Combustion is modelled using finite-rate chemical kinetics and a one-step overall reaction. The gas-phase solution is obtained using the quasi-steady equations of mass, momentum, species, and energy conservation. A new multi-component formulation, which is appropriate for use with the finite-volume method, was developed to accurately describe the mass diffusion. Droplet circulation is accounted for by solving the quasi-steady mass and m o m e n t u m conservation equations, for the liquid phase. The gas phase and liquid phase are coupled via interfacial conservation equations, and the complete set of governing equations is solved iteratively. Results for extinction velocity as a function of droplet diameter and freestream temperature are presented for an n-heptane droplet. Numerical predictions for n-heptane are in quantitative agreement with the limited n-heptane experimental data available in the literature, and in qualitative agreement with experimental results for a variety of fuels and over a wide range of ambient temperatures and droplet diameters. A linear dependence of the extinction velocity as a function of droplet diameter constitutes the present state of knowledge. This study predicts a non-linear dependence for small diameters (d < lmm) and a linear dependence only for large diameters (d < 2mm). The predictions also show that a form of the Damk6hler number at extinction can be correlated with the Reynolds number through the use of the transfer number and appropriate dimensionless activation and adiabatic flame temperatures. A correlation that accurately reproduces the numerical predictions for extinction velocity over a wide range of droplet diameters and ambient temperatures is presented.
06101881 On-line building energy prediction using adaptive artificial neural networks Yang, J. et al. Energy and Buildings, 2005, 37, (12), 1250-1259. While most of the existing artificial neural networks (ANN) models for building energy prediction are static in nature, this paper evaluates the performance of adaptive ANN models that are capable of adapting themselves to unexpected pattern changes in the incoming data, and therefore can be used for the real-time on-line building energy prediction. Two adaptive ANN models are proposed and tested: accumulative training and sliding window training. The computational experiments presented in the paper use both simulated (synthetic) data and measured data. In the case of synthetic data, the accumulative training technique appears to have an almost equal performance with the sliding window training approach, in terms of training time and accuracy. In the case of real measurements, the sliding window technique gives better results, compared with the accumulative training, if the coefficient of variance is used as an indicator.
06101882 Osmotic pressures studied using a simple equation-of-state and its applications Yokozeki, A. Applied Energy, 2006, 83, (1), 15-41. The authors have developed new equations for general osmotic pressures based on a simple equation of state for solutions. The present method is a completely different approach (directly solving the osmotic equilibrium), compared with the conventional formulation. The model equations are analytical and valid for the entire range of solute concentrations, but require numerical iterations to solve the osmotic pressure, which can be easily made by a simple NewtonRaphson method. The model calculations reveal highly rich and complex behaviours including critical phenomena in the osmotic pressure. Then, there was a demonstration that the present model can be applied successfully to actual osmotic data, such as aqueous polymer solutions and aqueous salt solutions of proteins using a single adjustable parameter, which has a physical meaning,
06/01883 Reliability optimization using ant colony algorithm under performance and cost constraints Meziane, R. et al. Electric Power Systems Research, 2005. 76. (1-3), 1-8. Reliability engineers often try to achieve a high reliability level of production systems. The problem of electrical network reliability optimization where redundant electrical devices are included is
06•01875 Hybrid algorithm based on EP and LP for security constrained economic dispatch problem Somasundaram, P. et al. Electric Power Systems Research, 2005, 76, (13), 77-85. This paper presents a new hybrid method for solving security constrained economic dispatch problem. The proposed method is developed in such a way that a simple evolutionary programming is applied as a base level search, which can give a good direction to the optimal global region and a local search linear programming is used as a fine tuning to determine the optimal solution. The hybrid approach outperforms the evolutionary programming based method and reduces the total computation time. A 10-bus and 66-bus Indian utility systems are considered to illustrate the effectiveness of the proposed method. The investigations reveal that the proposed method is suitable for practical utility systems.
06/01876 Isotope correlations for determining the isotopic composition of plutonium produced in research and power reactors using the experimental data obtained by alpha and mass spectrometry Aggarwal, S. K. and Alamelu, D. International Journal of Nuclear Energy Science and Technology, 2005, 1. (2-3), 215-219. Correlations have been developed for obtaining the isotopic composition of Pu produced in Indian research (CIRUS, D H R U V A ) and power (PHWR) reactors. The experimental data obtained on 238pu/ (239pu + 24°pU) a!pha activity ratio using alpha spectrometry and on 240 Pu/-n39 Pu, 241 Pu/" 39 Pu, 242 Pu/2 39 Pu atom ratios by thermal inoization mass spectrometry were used for developing isotope correlations.
06101877 Low-bandwidth open-loop control of combustion instability Uhm, J. H. and Acharya, S. Combustion and Flame, 2005, 142, (4), 348 363. A new strategy for open-loop control of combustion oscillations using a high-momentum air jet modulated at low frequencies is described. The oscillations in the swirl-stabilized spray combustor of interest are dominated by a longitudinal acoustic mode (235 Hz) with a lowfrequency (13 Hz) bulk mode (of the upstream cavity) superimposed. An effective strategy for control is demonstrated to be achieved through employment of a new concept that uses low-bandwidth, openloop modulation of a high-momentum air jet that penetrates directly into the region of strong combustion dynamics. It is shown that with low-frequency modulation (1-7 Hz) of the high-momentum air jet, the pressure oscillations can be reduced significantly (by a factor of nearly 10). Square-wave modulation is demonstrated to be considerably more effective than sine-wave modulation. These results are extremely promising as high-bandwidth actuation is not required for effective control.
06/01878 Mass spectrometric studies on irradiated (U, Pu) mixed carbide fuel of FBTR Balasubramanian, R, et al. International Journal of Nuclear Energy Science and Technology, 2005, 1, (2-3), 197-203. Mass spectrometry was employed to characterise the irradiated mixed carbide fuel of fast breeder test reactor (FBTR) for assessing its performance: thermal ionization mass spectrometry to determine the isotopic composition, concentrations of U, Pu and Nd in the dissolver solutions and to deduce the burn-up, and a quadrupole mass spectrometric system to obtain the percentage release of fission gases (Kr + Xe). A summary and analysis of the results obtained with the fuel at 25,000 and 50,000 MWd/t in these studies is given in this paper.
06•01879 Multi-component mathematical model of solid oxide fuel cell anode Hussain, M. M. et al. International Journal of Energy Research, 2005, 29, (12), 1083-1101. A mathematical model describing the multi-component species transport inside the porous solid oxide fuel cell (SOFC) anode has been developed. The model includes the water-gas shift reaction in the anode electrode (backing) layer and the spatially resolved electrochemical reaction in the reaction zone layer. The modified StefanMaxwell equations incorporating Knudsen diffusion were used to model multi-component diffusion inside the porous electrode (backing) and reaction zone layers. Moreover, the general Butler-Volmer equation was used to model the electrochemical reaction in the reaction zone layer. The model can predict the distribution of species
284
Fuel and Energy Abstracts
July 2006
within the SOFC anode for any reformate gas composition involving carbon dioxide, carbon monoxide, hydrogen and water vapour. The chemical and electrochemical reactions as well as transport processes in the SOFC anode can be simulated, yielding the anode performance under various operating and design conditions. This anode model can be coupled with a similarly developed model for the cathode to form an overall model for a single SOFC model,
06/01880 Numerical simulation of fuel droplet extinction due to forced convection Pope, D. N. and Gogos, G. Combustion andFlame, 2005, 142, (1-2), 89 106. The extinction of an envelope flame at the forward stagnation point of a liquid fuel droplet due to forced convection is numerically investigated. The droplet is oxidizing within an air stream at atmospheric pressure. Combustion is modelled using finite-rate chemical kinetics and a one-step overall reaction. The gas-phase solution is obtained using the quasi-steady equations of mass, momentum, species, and energy conservation. A new multi-component formulation, which is appropriate for use with the finite-volume method, was developed to accurately describe the mass diffusion. Droplet circulation is accounted for by solving the quasi-steady mass and m o m e n t u m conservation equations, for the liquid phase. The gas phase and liquid phase are coupled via interfacial conservation equations, and the complete set of governing equations is solved iteratively. Results for extinction velocity as a function of droplet diameter and freestream temperature are presented for an n-heptane droplet. Numerical predictions for n-heptane are in quantitative agreement with the limited n-heptane experimental data available in the literature, and in qualitative agreement with experimental results for a variety of fuels and over a wide range of ambient temperatures and droplet diameters. A linear dependence of the extinction velocity as a function of droplet diameter constitutes the present state of knowledge. This study predicts a non-linear dependence for small diameters (d < lmm) and a linear dependence only for large diameters (d < 2mm). The predictions also show that a form of the Damk6hler number at extinction can be correlated with the Reynolds number through the use of the transfer number and appropriate dimensionless activation and adiabatic flame temperatures. A correlation that accurately reproduces the numerical predictions for extinction velocity over a wide range of droplet diameters and ambient temperatures is presented.
06101881 On-line building energy prediction using adaptive artificial neural networks Yang, J. et al. Energy and Buildings, 2005, 37, (12), 1250-1259. While most of the existing artificial neural networks (ANN) models for building energy prediction are static in nature, this paper evaluates the performance of adaptive ANN models that are capable of adapting themselves to unexpected pattern changes in the incoming data, and therefore can be used for the real-time on-line building energy prediction. Two adaptive ANN models are proposed and tested: accumulative training and sliding window training. The computational experiments presented in the paper use both simulated (synthetic) data and measured data. In the case of synthetic data, the accumulative training technique appears to have an almost equal performance with the sliding window training approach, in terms of training time and accuracy. In the case of real measurements, the sliding window technique gives better results, compared with the accumulative training, if the coefficient of variance is used as an indicator.
06101882 Osmotic pressures studied using a simple equation-of-state and its applications Yokozeki, A. Applied Energy, 2006, 83, (1), 15-41. The authors have developed new equations for general osmotic pressures based on a simple equation of state for solutions. The present method is a completely different approach (directly solving the osmotic equilibrium), compared with the conventional formulation. The model equations are analytical and valid for the entire range of solute concentrations, but require numerical iterations to solve the osmotic pressure, which can be easily made by a simple NewtonRaphson method. The model calculations reveal highly rich and complex behaviours including critical phenomena in the osmotic pressure. Then, there was a demonstration that the present model can be applied successfully to actual osmotic data, such as aqueous polymer solutions and aqueous salt solutions of proteins using a single adjustable parameter, which has a physical meaning,
06/01883 Reliability optimization using ant colony algorithm under performance and cost constraints Meziane, R. et al. Electric Power Systems Research, 2005. 76. (1-3), 1-8. Reliability engineers often try to achieve a high reliability level of production systems. The problem of electrical network reliability optimization where redundant electrical devices are included is