Progress during the ninth quarter of a three-year study of ash formation and deposition was made in several areas. One of the key contributions this quarter was the development of an enhanced method for classification of CCSEM data. This classification algorithm permits grouping and comparison of particles previously labeled as ``unclassifiable.`` A second analytical advancement, also made this quarter, provides more detailed information on the distribution of minerals in the coal and the potential for coalescence. This new multiple analysis technique is also applicable to ash and will permit identification of heterogeneous ash particles. Additional analyses of ash samples were also performed and it was found that the firing of Pittsburgh {number_sign}8 under staged combustion conditions yields an ash with a significantly larger particle size distribution than that obtained under conventional firing conditions, but without a significant change in composition. the size difference was noted previously, but the new classification algorithm allowed a detailed comparison of all composition groups, including unclassifiable particles, in the ashes. A mechanistic explanation for this behavior has been developed and is provided in the report. Finally, a paper documenting the new classification algorithm has been prepared and is scheduled for presentation at the March ACS …

Reports on the feasibility of replacing existing embedded process piping with new more corrosion resistant piping between cells and between cells and a hot pipe trench of a Hanford Site style canyon facility. Provides concepts for replacement piping installation, and use of robotics to replace the use of the canyon crane as the primary means of performing/supporting facility modifications (eg, cell lining, pipe replacement, equipment reinstallation) and operational maintenenace.

The authors discuss, with illustrations drawn from the simple example of a dielectric grating under total internal reflection illumination, the use of electric field, energy density and Poynting vector as tools for understanding phenomena associated with dielectric gratings. The electric field has greatest direct observational interest, and exhibits patterns of nodes and antinodes that are both expected and intuitive. The energy density, though not directly linked with photoelectric response, has readily understood global patterns. The Poynting vector has more elaborate structure, involving patterns of curls, but the patterns are sensitive to small changes in illumination angle or groove depth. Plots of Poynting vectors may not be as useful for dielectric structures as they are for metals.