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Cokes were produced in an electrical furnace from a coal blend containing varying levels of added TiO2. The effects of TiO2 levels on coke structure and properties were then considered. Mercury int...

Four Chinese bituminous coals were analyzed using X-ray diffraction, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy, and the relationships between structural parameters and coal rank were then established. X-ray diffraction analysis reveals that amorphous and crystalline carbon types exist in coals, and average stacking heights and lateral sizes of the layer structures are various. Good correlations between coal crystalline volume, aromaticity and maximum vitrinite reflectance exist, reflecting their level of maturity. The Fourier-transform infrared spectroscopy analysis shows that A-factor, reflecting the coal hydrocarbon-generating potential, decreases with the increase of maximum vitrinite reflectance. Meanwhile, small values of C-factor and C=O/C=C show little amount of C=O components in coal samples. A good correlation between CH2/CH3 and R0 indicates that the length of aliphatic chains declines with the increase of coal rank. X-ray photoelectron spectroscopy analysis shows that the relative amounts of C–C and C–O groups rise with the increase of R0 value. The higher the R0 is, the lower the amount of C vacancy exists, which results in coal reactivity decreasing, all of which suggest that the variety of coal structure mainly depends on the coal rank.

Co-pyrolysis of biomass and coal was investigated as an effective way to reduce the greenhouse gas emission. The effects of poplar on the thermal behavior of fat coal were studied using thermogravimetric analyzer. The blended samples heated to characteristic temperature were subjected to attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to characterize the macromolecular structure. The results indicated that the synergistic effects existed in co-pyrolysis process of blends since lower char yield than calculated values, and the synergistic effects presented positive and negative trend with the increase of temperature, respectively. The carbonyl/carboxyl C=O stretching vibration functional groups and aliphatic side chain from individual fuels were decomposed in advance during co-pyrolysis. Furthermore, the hydrocarbon-generating potential (A-factor) and thermal maturity(C-factor) of the mixtures showed nonadditivity performance.

A surface MEMS miniature switch with the cantilevered arm has been made on low resistivity Si substrate. The switch was inserted into a time domain setup and their lifetimes have been characterized as a function of actuated voltage, demonstrating some relationship among lifetime and threshold voltage. The structure of MEMS RF switch is simulated by ANSYS software, doing some failure analysis and discussing difference comparing the experiment.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.