16 Fuel science and technology (fundamental science, analysis, instrumentation)

kinetic parameters were determined. Using the model with the kinetic parameters, temperature changes with time and drum-radius axes for the ASM-filled drum were numerically simulated assuming a one- dimensional infinite cylinder system, where the drum was being cooled at an ambient temperature of 50°C. The minimum filling temperature, at which the runaway reaction (MFTRR) can occur for the simulated ASM in the drum is about 194°C. Furthermore, a very good linear correlation exists between this MFTRR and the initial radius of salt particles formed in the bituminization product. The critical filling temperature to the runaway reaction is about 162°C for the asphalt- salt mixture, containing zero-size salt particles, filled in the same drum at an ambient temperature of 50°C. Thus, the runaway reaction will never occur in the drum filled with the asphalt-salt mixture under the conditions of the filling temperature below 162°C and a constant ambient temperature of 50°C. As a consequence, the ASM explosion occurred in the reprocessing plant likely was due to a slightIy exothermically reaction and self heating.

05/01854 Experimental investigation of heat-transfer characteristics of aluminum-foam heat sinks Hsieh, W. H. et al. International Journal of Heat and Mass Transfer, 2004, 47, (23), 5149-5157. The demand of high speed and miniaturization of electronic components results in increased power dissipation requirement for thermal management. In this work, the effects of porosity (e), pore density (PPI) and air velocity on the heat-transfer characteristics of aluminum-foam heat sinks are investigated experimentally. The phenomenon of non-local thermal equilibrium (NLTE) is also observed and reported. Results show that the Nu increases as the pore density increases, due to the fact that aluminum foam with a larger pore density has a iarger heat-transfer area. The Nusselt number also increases with the increase of porosity due to the same reason. It is noted that temperatures of the solid and gas phases of the aluminum foam decrease as Reynolds number increases, caused by the increased convective heat-transfer rate at higher Reynolds number. The deduced temperature difference between the solid and gas phases clearly indicates the existence of non-local thermal equilibrium condition within the aluminum-foam heat sink. The increase of the porosity and the pore density enhances the phenomenon of non-local thermal equilibrium. The temperature difference increases with the decrease of Reynolds number and the distance away from the heat source.

05101855 Experimental low temperature water content in gaseous methane, liquid ethane, and liquid propane in equilibrium with hydrate at cryogenic conditions Song, K. Y. et al. Fluid Phase Equilibria, 2004, 224, (2), 271-277. In low temperature gas processing, the presence of water can result in the formation of gas hydrate plugs. To avoid this problem, it is important to know the water solubility in natural gas components in equilibrium with gas hydrate. In this study experimental measurements of water content in gaseous methane in equilibrium with hydrate at 3.45 MPa (500 psia) and 6.90 MPa (1000 psia) and temperatures ranging from -3.2°C (26.2 °F) to -80°C ( -112 °F) are presented. Similar measurements are presented for liquid ethane at 3.45 MPa (500 psia) and temperatures from -2.2°C (28.0 °F) to -70°C ( -94 °F), and for liquid propane at 0.86 MPa (125 psia) and temperatures down to -60°C ( -76 °F), respectively. In measuring the water content, a Panametrics moisture sensor (calibrated to 1 ppb water content in nitrogen) has been used in flowing streams of the hydrocarbon-rich phases that are saturated with water. The results obtained with the Panametrics hygrometer show good agreement (normally better than -~4%) with previous measurements, which were obtained by a gas chromatographic technique for methane, ethane, and propane at temperatures ranging from -2.0°C (28.4 °F) to -30°C ( -22 °F), which are within the hydrate region.

05•01856 Experimental results from noise measurements in a source driven subcritical fast reactor Rugama, Y. et al. Progress in Nuclear Energy, 2004, 44, (1), 1-12. Both pulse counting techniques and continuous current measurements have been applied in the MASURCA subcritical fast reactor driven by the GENEPI pulsed neutron source in order to get the prompt neutron decay constant. The data from the pulse counting experiments were analysed using auto- and cross-correlation techniques, which are similar to one- and two-detector Rossi-c~ measurements, and Feyn- man-(x techniques. The data from the continuous current measure- ments were analysed by calculating the cross power spectral density (CPSD). Good agreement was found between the values extracted from the auto- and cross-correlation techniques and from the cross- covariance and CPSD. The application of the time domain techniques becomes easier when there is no overlapping of the neutron chains originating from different source pulses. The application of the Feynman-c~ method shows some problems for pulsed systems, because of the dominance of the periodic terms in the variance-to-mean ratio, which leaves very little information to fit the prompt neutron decay

constant. However, good agreement exists between the results and predictions from literature. Of the methods studied, CPSD is shown to be the best of the noise techniques to get the reactor decay time constant. It is applicable for a wide range of source frequencies and it converges rapidly comparing with subcritical systems driven by a radioactive source. In general, it was concluded that the noise analysis techniques applied here are applicable to pulsed source driven systems.

05/01857 Generalized relationship for determining soil electrical resistivity from its thermal resistivity Sreedeep, S. et al. Experimental Thermal and Fluid Science, 2005, 29, (2), 217-226. The knowledge of soil electrical and thermal resistivity finds its application in many of the real life engineering projects like laying of high voltage buried power cables, ground modification techniques etc. This necessitates determination of soil electrical resistivity and thermal resistivity and development of a relationship between them. However, as these resistivities mainly depend on the type of the soil (i.e. its physical composition) and its saturation, efforts have been made in this paper, to develop a generalized relationship to relate them. Validation of the relationship has been conducted vie-d-vie the results obtained from the laboratory experiments and those reported in literature.

05•01858 Heat recirculation and heat transfer in porous burners Barra, A. J. and Ellzey, J. L. Combustion and Flame, 2004, 137, (1-2), 230-241. Flames stabilized within porous media differ from conventional flames primarily due to the heat recirculation provided by the solid matrix. Heat is recirculated through solid conduction and solid-to-solid radiation from the matrix downstream of the flame to the matrix upstream of the flame. Solid-to-gas convection upstream of the flame preheats the incoming reactants, resulting in enhanced flame speeds and locai temperatures above the adiabatic flame temperature. In this paper, the heat recirculation in a porous burner is analysed using a one-dimensional t ime-dependent formulation with complete chemistry. The enhancement of flame speed is presented in terms of a ratio between the effective flame speed of a flame in a porous medium and the laminar flame speed. A heat recirculation efficiency is defined as a percentage of the firing rate transferred into the preheat zone. The importance of solid conduction and solid-to-solid radiation is discussed for various stable operating conditions. The radiant output efficiency is also presented. In addition, discussions of peak and exit gas temperature trends are included. Results indicate that with increasing equivalence ratio, heat recirculation efficiency decreases. Both solid conduction and radiation play important roles in the heat transfer process. In addition, the results indicate that the observed trends are valid for burners of various lengths.

05/01859 Helmholtz energy, extended corresponding states and local composition model for fluid mixtures Estela-Uribe, J. F. et al. Fluid Phase Equilibria, 2004, 224, (1), 125-142. This paper presents a model for the calculation of mixture properties. This model is based on the mixture residual Helmholtz energy given by the sum of two terms: one is the residual Helmholtz energy calculated by an extended corresponding states (ECS) model while the other is a correction term. The ECS model is based on methane as the reference fluid and shape factors that carry out the scaling of properties between the fluid of interest and the reference fluid. These shape factors are given by correlations in terms of reduced temperature and density. The application to mixtures is carried out with the one-fluid van der Waals mixture model. The correction term is temperature- and density- dependent as is given by a local composition mixing rule. Local compositions were calculated fi'om a coordination number model based on lattice gas theory. With respect to binary-mixture properties, densities were calculated with an average absolute deviation (AAD) of 0.12%; speeds of sound were calculated with an AAD of 0.16% and bubble pressures were calculated with an AAD of 1.77%. Also, natural gas densities were calculated with AAD of 0.03% and natural gas speeds of sound were calculated with AAD of 0.049%. All these results are very satisfactory when compared with those obtained by modern mixture models.

05•01860 Hyperspectral detection of geothermal system- related soil mineralogy anomalies in Dixie Valley, Nevada: a tool for exploration Nash, G. D. et al. Geothermics, 2004, 33, (6), 695-711. Hyperspectral data analysis has been applied to the mapping of soil anomalies that may be related to present or past geothermal systems. Anomalous accumulations of certain soil minerals can indicate buried geologic structures and possible zones of elevated permeability. Hyperspectral data can be used to map these anomalies as part of geothermal exploration activities. The study area for this project was northern Dixie Valley, Nevada, which is host to a structurally- controlled deep-circulation hydrothermal convection system. Advanced

Fuel and Energy Abstracts July 2005 271