The memory consistency model in a language defines the order in which the results of write operations maybe observed through read operations. The behavior of a UPC program may depend on the timing of accesses to shared variables, so a program defines a set of possible executions, rather than a single execution. The memory consistency model constrains the set of possible executions for a given program; the user may then rely on properties that are true of all of those executions. The memory consistency model is defined in terms of the read and write operations issued by each thread in naive translation of the code, i.e., without any code transformations by the compiler, with each thread issuing operations as defined by the abstract machine defined in ISO C 5.1.2.3. A UPC compiler or run time system may perform various code transformations to improve performance, so long as they are not visible to the programmer - i.e., provided the set of externally-visible behaviors (the input/output dynamics and volatile behavior defined in ISO C 5.1.2.3) from any execution of the transformed program are identical to those of the original program executing on the abstract machine and adhering to the consistency model defined …

In this reporting period, we continued full disc prototype manufacturing. The vacuum offgas system no longer leaks and was modified to include a vapor condenser and a by-pass for argon purge. Two sand molds were made with an oxidation prevention agent and steel mandrels inserted in the center holes to reduce shrinkage restriction. A copper coating was applied between H13 and WC inserts. The two sand molds are ready to be HIPped and examined next quarter.

Nucleation-growth kinetic expressions are derived for thermal decomposition of HMX from a variety of types of data, including mass loss for isothermal and constant rate heating in an open pan, and heat flow for isothermal and constant rate heating in open and closed pans. Conditions are identified in which thermal runaway is small to nonexistent, which typically means temperatures less than 255 C and heating rates less than 1 C/min. Activation energies are typically in the 140 to 150 kJ/mol regime for open pan experiments and about 160 kJ/mol for sealed pan experiments. Our activation energies are about 10% lower than those derived from data supplied by the University of Utah, which we consider the best previous work. The reaction clearly displays more than one process, and most likely three processes, which are most clearly evident in open pan experiments. The reaction is accelerated for closed pan experiments, and one global reaction appears to fit the data well.

Precipitation scavenging can effectively remove particulates from the atmosphere. Therefore, this process is of importance in the real-time modeling of atmospheric transport for hazardous materials. To account for the rainfall effect in LLNL operational dispersion model, a modified version of a standard below-cloud aerosol scavenging model has been developed to handle the emergency response in this scenario (Loosmore and Cerdewall, 2003, hereafter referred to as LC). Two types of rain data can be used to incorporate precipitation scavenging in the dispersion model; realtime measurements (rain gauge and radar), and model prediction. The former approach has been adopted in LC's study for the below-cloud scavenging problem based on the surface rain measurements. However, the in-cloud scavenging effect remains unresolved as a restriction of available real-time measurements in providing the vertical structure of precipitation systems. The objective of this study is to explore the possibility to incorporate three-dimensional precipitation structure of forecast data into the dispersion model. Therefore, both in-cloud and below-cloud scavenging effects can be included in LLNL aerosol scavenging model. To this end, a mesoscale model (Naval Research Laboratory 3-D weather forecast model, COAMPS) is used to demonstrate this application using a mid-west severe storm case occurring on July 18, …

This report summarizes the work done on the project over the duration of the project, from October 1, 2002 through December 31, 2003, which includes a three month no-cost extension. Effort was directed in the following areas: (1) Fabrication of Sr-doped LaCoO3 (LSC) dense and porous samples. (2) Design and construction of a conductivity relaxation apparatus for the estimation of surface exchange coefficient, k{sub chem}, which depends on adsorption, and oxygen chemical diffusion coefficient, {tilde D}{sub 0}, the parameters which are thought to describe the cathodic activation polarization (overall charge transfer) in mixed ionic electronic conducting (MIEC) cathodes. (3) The measurement of and K{sub chem} and {tilde D}{sub 0} on LSC by conductivity relaxation, as a function of temperature and oxygen partial pressure, p{sub O{sub 2}}. (4) Fabrication of YSZ electrolyte discs with patterned LSM and LSC electrodes with three-phase boundary (TPB) length, l{sub TPB}, varying between 50 and 1200 cm{sup -1}. (5) The measurement of charge transfer resistance, R{sub ct}, and estimation of the charge transfer resistivity, {rho}{sub ct}, as a function of temperature and p{sub O{sub 2}}, and the incorporation of the adsorption step in the analysis. (6) Preliminary cell tests with oxidants having different inert gas diluents; …

Summary of Recent Field Testing: Extensive in situ (in ground) field testing using the push-pull method has demonstrated that indigenous microorganisms in the shallow (< 8 m) aquifer in FRC Areas 1 and 2 are capable of coupling the oxidation/fermentation of injected ethanol, glucose, or acetate to the reduction of U(VI) and Tc(VII). Despite highly variable initial (prior to testing) contaminant concentrations (pH: 3.3-7.2; Nitrate: 0.1-140 mM; U(VI): 1-12 uM; Tc(VII): 200-15000 pM), sequential donor additions resulted in increased rates of microbial activity (Denitrification: 01.-4.0 mM/hr; sulfate reduction: 0- 0.03 mM/hr; U(VI) reduction: 10-4 to 10-3 uM/hr; Tc(VII) reduction: 4-150 pM/hr) in all wells tested. Tc(VII) reduction and denitrification proceeded concomitantly in all tests. U(VI) reduction was concomitant with Fe(II) production in Area 1 but little Fe(II) was detected under sulfate reducing conditions in Area 2. Reoxidation of U(IV) (precipitated in the vicinity of the wells during previous tests) but not Tc(IV) was observed when injected test solutions contained initial nitrate concentrations > {approx} 20 mM. Field data and laboratory studies suggest that U(IV) is likely oxidized by Fe(III) minerals produced by enzymatic Fe(II) oxidation or by Fe(II) oxidation by nitrite. U(IV) reoxidation rates (10-3 to 10-2 uM/hr) were somewhat …