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

observed in it. To comnare with the suectra, spontaneous emission spectra from the pre-Gapourized flamk of keiosene mixture were measured.

03/00929 Analytical methodology and boundary problem for computing temperature and thermal stresses in tubes Cardella, A. Heat and Technology (Pisa, Italy), 2002, 20, (l), 61-67. The namer nresents an analvsis method to commute the temnerature and ih&rnai stress distribution in a tube, whi& receives an ‘external heat flux and has a constant internal volumetric heating. The analvsis method can be used for different heat flux distribut&ms alone. ‘the external surface of the tube. Typical out-of-plane boundary condzions are evaluated, and thermal strksses are obtained for three_tvDical out- of-plane boundary conditions, the plane strain, the general &ne strain with allowed rotations. and the general olane strain wi& restrained rotations. The anal& solution”was deieloped for high heat flux comnonents such as those of thermonuclear fusion reactors. studving in a sir&le geometry the effect of the different boundary conhitio& ind it was’ u&d as a Benchmark to check results of finite *element analyses (FEM). It may be used for other similar comDonents, in uarticular & a iuick computing tool for optimization or sizi& analyses.-The solutions Gave been- de&loped for ‘high heat flux components such as fusion reactor.

03/00930 Application of the exergetic cost theory to the LiBr/H*O vapour absorption system Misra, R. D. et al. Energy, 2002, 27, (1 l), 1009-1025. Optimization of thermal systems is czenerallv based on thermodvnamic an’alysis. However, the systems so o&mized-often are not viable’due to economic constraints. -The Theo& of Exergetic Cost. a thermo- , economic optimization technique, combines the thermodynamic analvsis witc that of economic- constraints to obtain an odtimum con&uration of a thermal system. In this paper, this tech&que is applied to optimize a LiBr/H& vapour absor&on refrigeration sistem run bv pressurized hot water for air-conditioning armlications. The mathimatical and numerical techniques-based opt&&a&on of thermal systems is not always possible due to plant complexities. Hence, a simplified cost minimization methodology, based on ‘theory of exergetic cost’, is applied to evaluate the economic costs of all the internal flows and products of the system under consideration. As shown in this paper, once these costs are determined, an approximately optimum design configuration can be obtained.

03/00931 Atomic-level understanding of CO2 mineral carbonation mechanisms from advanced computational modeling Chizmeshya, A. V. G. et al. Proceedings of the International Technical Conference on Coal Utilization & Fuel Systems, 2002, 2, (27), 803-814. Conversion of stationary-source carbon dioxide emissions into mineral carbonates has recently emerged as one of the most promising carbon sequestration options, providing permanent CO2 disposal, rather than storage. Mg-rich serpentine-based minerals represent particularly attractive feedstock candidates for the process due to their vast natural abundance and low-cost. Minimizing the process cost via optimization of the reaction rate and degree of completion is the remaining challenge. As discussed in the preceding article, the chemical processes involved in the mineral decomposition and carbonation are quite complex and a detailed understanding and interpretation is challen- ging. In this companion article the authors discuss how first-principles computational solid-state and materials simulation methodology has been used to elucidate and synthesize new conceptual understanding, with a special emphasis on the serpentine heat-treatment process described in the previous article.

03/00932 Atomistic computer simulations for thermodynamic properties of carbon dioxide at low temperatures Kuznetsova, T. and Kvamme, B. Energy Conversion and Management. 2002, 43, (18), 2601-2623. Investigation into the volumetric and energetic properties of two atomistic models mimicking carbon dioxide geometry and quadrupole moment covered the liquid-vapour coexistence curve. Thermodynamic integration over a polynomial path was used to calculate free energy. Computational results showed that the model using GROMOS Lennard-Jones parameters was unsuitable for bulk or interface CO1 simulations. On the other hand, the model with potential fitted to reproduce only the correct density-pressure relationship in the supercritical region proved to yield the correct enthalpy of vapouriza- tion and free energy of liquid CO2 in the low temperature region. NPT molecular dynamics was used to estimate the water-CO2 interfacial tension and solubilities at 276 K for a liquid-liquid system at 100 and 300 atm.

03/00933 Calculation of the heats of combustion of saturated hydrocarbons contained in power-generating fuels Sagadeev, E. V. and Sagadeev, V. V. High Temperature (Tratwlation of Teplqfl’zika Vysokikh Temperatur), 2002, 40, (4), 537-54 I. An empirical method is suggested for the calculation of the heats of combustion of saturated hydrocarbons by the additive scheme proceeding from their chemical structure.

03/00934 Computer model and its validation for prediction of storage effect of water mass in a greenhouse: a transient analysis Gupta, A. and Tiwari, G. N. Energjt Conversion arlti Management, 2002, 43, (18), 2625-2640. In the present paper, an attempt has been made to develop a computer model based on transient analysis of the greenhouse. The model predicts room air temperature, storage water temperature and the thermal energy storage effect of a water mass in a low cost, passive greenhouse. Analytical expressions, based on an energy balance for each component, have been derived in terms of climatic as well as design parameters. Numerical computations have been done on typical days for the months from December 1999 to June 2000 at New Delhi. It has been observed that (i) there is a significant thermal energy storage effect of the water mass on room temperature and (ii) thermal load levelling, which is found to decrease with an increase in the mass of storage water, varies with month of year. An experimental validation of the developed model has also been demonstrated. The predicted room and water iemperature show fair agreement with experimental values.

03/00935 Contaminant transport in finite fractured porous medium: integral transforms and lumped-differential formulations Cotta, R. M. et al. Annals of Nuc/rar Energ! . 2003. .W. (3), 261-285. Mass transfer within saturated porous media wilh discrete finite fractures is examined, by simultaneously solving the convection- diffusion equation for the contaminant transport along the fracture and the two-dimensional diffusion equation for contamination within the porous matrix. A lumped-differential formulation based on Hermite integration is proposed for the porous matrix thus eliminating the dependence on the transverse direction. The resulting coupled partial differential equations are then handled through the generalized integral transform technique (GITT), which yielcls analytical ex- pressions for the space dependence and numerical estimates for the concentration fields as a function of time. Different analytical filtering strategies are proposed and analysed in terms of comergence rates. An illustrative example is considered for both the constant and time- variable contamination physical situations.

03/00936 Determination of paraffin and aromatic hydrocarbon type chemicals in liquid distillates produced from the pyrolysis process of waste plastics by isotope- dilution mass spectrometry Seo, Y.-H.. and Shin, D.-H. Fuel, 2002, 81. (16). 2103-21 12. Isotope dilution mass spectrometry was developed for the determi- nation of composition of paraffins, olefins, naphthenes and aromatics in distilled oil produced from the pyrolysis reaction of mixed waste plastics using labelled hydrocarbon internal standards including octane-dl8, dodecane-d26, hexadecane-d34, benzene-d6, toluene-d8, ethylbenzene-dl0, 1,3,5-trimethylbenzene-dl2 and naphthalene-d8. This technique made it possible to thoroughly quantify more than three hundred peaks in plastic-derived pyrolysis oil, classify pyrolysis oil into four hydrocarbon groups of paraffin, olefin, naphthene and aromatic, and determine the weight percent of each hydrocarbon group simultaneously. Compared with commercially available petroleum oil, distilled plastic-derived pyrolysis oil contained much more aromatics amounting to 60-82 wt% of whole hydrocarbons. Toluene (C7- benzene) and trimethylbenzenes (C9-benzenes) were the predominant species amounting to 40-50% of whole hydrocarbons in pyrolysis oil with a gasoline range boiling point and 25-35?? of whole hydrocarbons in pyrolysis oil with a diesel range boiling point, respectively.

03/00937 Electron backscatter diffraction of a plutonium- gallium alloy Boehlert, C. J. et al. Journal of Nuclear Materials, 200.3, 312, (l), 67-75. An experimental technique has recently been developfzd to characterize reactive metals, including plutonium (Pu) and ceriurn, using electron backscatter diffraction (EBSD). Microstructural char,lcterization of Pu and its alloys by EBSD had been previously elusive primarily because of the extreme toxicity and rapid surface oxidation rate associated with Pu metal. The experimental technique, which included ion-sputtering the metal surface using a scanning Auger microprobe (SAM) followed by vacuum transfer of the sample from the SAM to the scanning electron microscope (SEM), used to obtain electron backscatter diffraction Kikuchi patterns and orientation maps for a Pu-gallium alloy is described and the initial microstructural observations based on

Fuel and Energy Abstracts May 2003 187