Motion-dependent fluids forces acting on a tube array were measured as a function of excitation frequency, excitation amplitude, and flow velocity. Fluid-damping and fluid-stiffness coefficients were obtained from measured motion-dependent fluid forces as a function of reduced flow velocity and excitation amplitude. The water channel and test setup provide a sound facility for obtaining key coefficients for fluid-elastic instability of tube arrays in crossflow. Once the guideline, based on the unsteady flow theory, can be developed for fluid-elastic instability of tube arrays crossflow.

A tube array supported by baffle plates in crossflow may be subjected to fluid-elastic instability in the tube-support-plate-inactive mode. An experimental study is presented to characterize the tube motion. Three series of tests were performed to measure tube displacements as a function of flow velocity for different clearances. The motion was examined by root-mean-square values of tube displacements, power spectral densities, phase planes, Poincare maps, and Lyapunov exponents. The experimental data agree reasonably well with the analytical model, based on the unsteady flow theory.

Message passing is a common method for writing programs for distributed-memory parallel computers. Unfortunately, the lack of a standard for message passing has hampered the construction of portable and efficient parallel programs. In an attempt to remedy this problem, a number of groups have developed their own message-passing systems, each with its own strengths and weaknesses. Chameleon is a second-generation system of this type. Rather than replacing these existing systems, Chameleon is meant to supplement them by providing a uniform way to access many of these systems. Chameleon`s goals are to (a) be very lightweight (low over-head), (b) be highly portable, and (c) help standardize program startup and the use of emerging message-passing operations such as collective operations on subsets of processors. Chameleon also provides a way to port programs written using PICL or Intel NX message passing to other systems, including collections of workstations. Chameleon is tracking the Message-Passing Interface (MPI) draft standard and will provide both an MPI implementation and an MPI transport layer. Chameleon provides support for heterogeneous computing by using p4 and PVM. Chameleon`s support for homogeneous computing includes the portable libraries p4, PICL, and PVM and vendor-specific implementation for Intel NX, IBM EUI (SP-1), and …

A preliminary waste treatment plan was developed for disposing of radioactive inorganic liquid wastes that contain hazardous metals and/or hazardous acid concentrations at Argonne National Laboratory. This plan, which involves neutralization and sulfide precipitation followed by filtration, reduces the concentration of hazardous metals and the acidity so that the filtrate liquid is simply a low-level radioactive waste that can be fed to a low-level waste evaporator.

Annual report of the Argonne National Laboratory Chemical Technology Division (CMT) discussing the group's activities during 1992. These included electrochemical technology; fossil fuel research; hazardous waste research; nuclear waste programs; separation science and technology; integral fast reactor pyrochemical processes; actinide recovery; applied physical chemistry; basic chemistry research; analytical chemistry; applied research and development; and computer applications.