Computational modeling/simulation

Seiber, J.N., McChesney, M.M. (1987) Measurement and computer model simulation of the volatilization flux of molinate and methyl parathion from a flooded rice field. Final Report to the Department of Food and Agriculture, Sacramento, California. 

A limited number of sink effect studies have been conducted in full-sized environments. Tichenor et al. [20] showed the effect of sinks on indoor concentrations of total VOCs in a test house from the use of a wood stain. Sparks et al. [50] reported on test house studies of several indoor VOC sources (i.e., p-dichlorobenzene moth cakes, clothes dry-cleaned with perchloroethylene, and aerosol perchloroethylene spot remover) and they were compared with computer model simulations. These test house studies indicated that small-chamber-derived sink parameters and kj) may not be applicable to full-scale, complex environments. The re-emission rate (kj) appeared to be much slower in the test house. This result was also reported by other investigators in a later study [51]. New estimates of and were provided,including estimates of fca (or deposition velocity) based on the diffusivity of the VOC molecule [50]. In a test house study reported by Guo et al. [52], ethylbenzene vapor was injected at a constant rate for 72 h to load the sinks. Re-emissions from the sinks were determined over a 50-day period using a mass-balance approach. When compared with concentrations that would have occurred by simple dilution without sinks, the indoor concentrations of ethylbenzene were almost 300 times higher after 2 days and 7 times higher after 50 days. Studies of building bake-out have also included sink evaluations. Offermann et al. [53] reported that formaldehyde and VOC levels were reduced only temporarily by bake-out. They hypothesized that the sinks were depleted by the bake-out and then returned to equilibrium after the post-bake-out ventilation period. Finally, a test house study of latex paint emissions and sink effects again showed that... 

Gallego R. and Ortiz M., A Harmonic/Anhamionic Energy Partition Method for Lattice Statics Computations, Modelling Simul. Mater. Sci. Eng. 1, 417 (1993). 

Use of low and perhaps unrepresentative analytical values for total Al and difunctional CAA concentrations may be one reason why mass balance calculations and computer model simulations of formation waters produce results that de-emphasize the role of organo-metallic complexes in the subsurface transportation of Al and Si (1.2.72.79). In addition, the thermodynamic constants for organo-metallic complexation by these species are unknown at elevated temperatures, and van t Hoff-type approximations used in many models may not be valid as the temperature extrapolation is too large. Complexation and transportation of Al and Si by polar organic compounds remain the only viable mechanism to explain the widespread Al and Si mobility noted in many clastic hydrocarbon reservoirs (3.35.39). 

One word of caution is necessary with respect to the experimentally derived biological activities. These should constitute pure receptor binding affinities and must stem from a single laboratory. Since the computer models simulate molecular interaction events in a highly simplified... 

S. Nam Development of a computational model simulating the interaction between a fire plume and a sprinkler spray. Fire Saf. J. 26, 1-33 (1996). 

In view of the low mobility of uranium in the soil and the small transfer factors into biological material, long-term effects on the environment should not be expected. Analysis conducted with the use of RESARD computer model simulations led to the conclusion that in the Balkans, on a long-time scale (several hundreds of years) the main risk for the population from deposited DU penetrators can be connected with possible contamination of drinking water in local wells which critically depends on various hydrogeological parameters which need to be evaluated at the site. On the other hand, it seems to be a reasonable assumption that a main exposure pathway for Kuwait s and southern Iraq s inhabitants is the uptake of uranium into the body by inhalation due to resuspension of DU present in surface soil or sand in the specific dry climatic conditions. 

Description of Experiments The Falcon Series of liquefied natural gas (LNG) spill experiments was performed by LLNL during the summer of 1987. These were the first tests performed at DOE s permanent Spill Test Facility. A series of five spills was performed on water within a vapor barrier structure as part of a joint government/industry study. These experiments were performed to evaluate the effectiveness of vapor fences as a mitigation technique for accidental releases of LNG. They also provided a database for the validation of wind tunnel and computer modeling simulations of vapor fence effects on LNG dispersion. Spills were made onto a water pond equipped with a circulation system to maximize evaporation to make the source evaporation rate as nearly equal to the spill rate as possible. 

The behavior of a bubble rising in a liquid or liquid solid suspension can be simulated by the computational model. Simulated results and experimental observations of a single bubble rising in a liquid... 

The data obtained is being used to test numerical procedures and codes. A sensitive analysis was performed and most sensitive parameters were identified. A representative group of transients were selected, in order to check computer models. Simulation models are in current development against a reference transient, without adjustment. When this contrast is clear, models will be compared against the representative group of transients. The information on specific models should be incorporated into CAREM modelling. 

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