In this paper we look at a number of approaches being investigated in the Center for Research on Parallel Computation (CRPC) to develop linear algebra software for high-performance computers. These approaches are exemplified by the LAPACK, templates, and ARPACK projects. LAPACK is a software library for performing dense and banded linear algebra computations, and was designed to run efficiently on high performance computers. We focus on the design of the distributed memory version of LAPACK, and on an object-oriented interface to LAPACK. The templates project aims at making the task of developing sparse linear algebra software simpler and easier. Reusable software templates are provided that the user can then customize to modify and optimize a particular algorithm, and hence build a more complex applications. ARPACK is a software package for solving large scale eigenvalue problems, and is based on an implicitly restarted variant of the Arnoldi scheme. The paper focuses on issues impact...

Fluidized-bed biological reactors (FBBRs) may be used to remove chloroethenes such as trichloroethene (TCE) from groundwater. Proper selection of FBBR aqueous growth medium, biofilm solid support media type and size, and bed charge (bed depth to column length fraction) are critical for establishing a biomass of sufficient quantity and activity to transform TCE via aerobic cometabolism, which requires a supplemental growth substrate. Thus, proper media selection involves facilitating efficient conversion of growth substrate to cometabolic activity for TCE degradation. In this study, five types of sand media (quartz, garnet, ilmenite, hematite, and magnetite) were evaluated in small-scale FBBRs under different conditions of media charge, size, and type. Also, biofilm growth and TCE degradation rates were measured for three aqueous growth media with phenol as the growth substrate: mineral salt waters (MSW), groundwater with excess nutrients (NGW), and amended groundwater with 10 times excess nutrients (AGW). MSW produced the highest level of biomass and highest TCE degradation rates, but the other media were selected for use in the FBBRs due to practical considerations. Differences in biofilm cometabolic properties were related to carbonate versus phosphate buffering of the growth media. Biofilms grown in the small-scale FBBRs on the different sand media were harvested and assayed for their maximum specific TCE degradation rate (k c) and transformation capacity (T

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