The second major ash producing mechanism is the generation of a submicron aerosol through a vaporization/condensation mechanism. When the ash size distribution is plotted in terms of number density, the submicron mode generally peaks at about 0. 1 [mu]m. When plotted in terms of mass, this mode is sometimes distinct from the residual ash mode, and sometimes merged into it. During diffusion-limited char combustion, the interior of the particle becomes hot and fuel-rich. The non-volatile oxides (e.g., Al[sub 2]O[sub 3], SiO[sub 2], MgO, CaO, Fe[sub 2]O[sub 3]) can be reduced to more volatile suboxides and elements, and partially vaporized. These reoxidize while passing through the boundary layer surrounding the char particle, thus becoming so highly supersaturated that rapid homogeneous nucleation occurs. This high nuclei concentration in the boundary layer promotes more extensive coagulation than would occur if the nuclei were uniformly distributed across the flow field. The vaporization can be accelerated by the overshoot of the char temperature beyond the local gas temperature. Although these particles represent a relatively small fraction of the mass, they can present a large fraction of the surface area. Thus, they are a preferred site for the condensation of the more volatile oxides later in …

During the period 1/9/93--4/8/93 a total of 39 samples (25 DOE Sample Bank samples and 14 other Penn State samples) of various sizes, not including DECS-17, were distributed. Twenty-two of these samples were provided to DOE contractors. During the current reporting period a total of 57 data printouts were distributed. In addition, 13 special data requests were fulfilled by either search/sort and printout or creation of a data disk, resulting in distribution of limited information on over 1130 samples. Several preliminary requests for Sample Bank and Data Base information and price quotations have also been handled.

This report describes an approach for calculating radiation doses for the Hanford Environmental Dose Reconstruction Project. The approach utilizes the CIDER computer code.

Achievements during the last 12 months of funding to initiate a Center of Excellence in biomedical laser development include: seven specific research projects within the Center`s three broad interest areas, and program development to establish the MGH Laser Center and its activities. Progress in the three interest areas namely new medical laser systems development, optical diagnostics and photo sensitization is reported. Feasibility studies and prototype development were emphasized, to enhance establishing a substantial Center through future support. Specific projects are outlined below. In addition, the interdepartmental MGH Laser Center`s activities and accomplishments.

The second major ash producing mechanism is the generation of a submicron aerosol through a vaporization/condensation mechanism. When the ash size distribution is plotted in terms of number density, the submicron mode generally peaks at about 0. 1 {mu}m. When plotted in terms of mass, this mode is sometimes distinct from the residual ash mode, and sometimes merged into it. During diffusion-limited char combustion, the interior of the particle becomes hot and fuel-rich. The non-volatile oxides (e.g., Al{sub 2}O{sub 3}, SiO{sub 2}, MgO, CaO, Fe{sub 2}O{sub 3}) can be reduced to more volatile suboxides and elements, and partially vaporized. These reoxidize while passing through the boundary layer surrounding the char particle, thus becoming so highly supersaturated that rapid homogeneous nucleation occurs. This high nuclei concentration in the boundary layer promotes more extensive coagulation than would occur if the nuclei were uniformly distributed across the flow field. The vaporization can be accelerated by the overshoot of the char temperature beyond the local gas temperature. Although these particles represent a relatively small fraction of the mass, they can present a large fraction of the surface area. Thus, they are a preferred site for the condensation of the more volatile oxides later in …

This project was designed to perform several tasks to provide transfer of technology to PNL concerning optimization of a cesium-specific ion exchange resin, developed at WSRC. The tasks support the development of a Compact Processing Unit (CPU) for Cs-removal from a variety of waste streams at Westinghouse Hanford (WH). In a series of experiments, WSRC has studied the behavior of a small column of the resin at various, increasingly greater flow rates with the HW simulant solution to determine an optimum column loading rate. Elution studies of the resin after saturation with Cs+ will generate an elution profile from which an optimum elution medium, flow rate, and volume can be determined. Small column tests at temperatures ranging from 40{degrees}C 80{degrees}C are planned but have not yet begun. Further, WSRC has begun a study in which the resin is subjected to ionizing radiation in a Co-60 source. This study will determine if any flammable or hazardous compounds, that might require special process controls, are formed as a result of irradiation. it will also define the ability of the resin to maintain its selectivity and capacity in a radiation field. During this period, a literature survey of the effects of radiation on …

The Clinton Administration and the 103rd Congress are in the early stages of a major review of U.S. trade, international and security relations with Japan, the principal U.S. ally and trading partner in Asia. A number of recent developments have raised tensions in this mutually beneficial relationship, which is still characterized by deepening economic interdependence and close political and security cooperation. These include the end of the Cold War, which has eliminated a common military threat; the recent renewed rise in Japan's trade surplus after several years of decline; and increasing international assertiveness by Japan, sometimes in conflict with U.S. policy.