Most research on polymer degradation is for single polymers, even though the thermal decomposition of polymer mixtures is of interest both practically and theoretically. Polymer degradation rates depend on the mixture type, and adding a polymer can increase, decrease, or leave unchanged the degradation rate of the first polymer. We show how distribution-kinetics theory, based on molecular-weight distributions (MWDs), provides expressions for degradation rates of binary polymer mixtures. The approach accounts for initiation, termination, hydrogen abstraction, and radical chain scission in the governing equations for MWDS. Molecular-weight moments yield expressions for molar and mass concentrations and rate coefficients for combinations of random and chain-end scission. Experimental data show the concentration effect of poly((x-methyl styrene)) (PAMS) on the degradation of polystyrene dissolved in mineral oil at 275 {degrees}C in a batch reactor. Samples analyzed by gel permeation chromatography yielded the time evolution of the MD. The results indicated that, owing to the interaction of mixed radicals with polymer by hydrogen abstraction, polystyrene degradation rate decreases with increasing PAMS concentration.

Lawrence Livermore National Laboratory's Earth and Environmental Sciences 1999 Annual Report covers the following topics: (1) Nuclear Materials--Modeling Thermohydrologic Processes at the Proposed Yucca Mountain Nuclear-Waste Repository; Dose Assessments and Resettlement Support on Rongelap Atoll in the Marshall Islands. (2) Climate, Carbon, and Energy--Incorporating Surprise into Models of Global Climate Change: A Simple Climate Demonstrator Model; (3) Environmental Risk Reduction--The NASA Global Modeling Initiative: Analyzing the Atmospheric Impacts of Supersonic Aircraft; (4) National Security--Atmospheric Release Assessment Programs; and (5) Cross-Cutting Technologies/Capabilities--Advances in Technology at the Center for Accelerator Mass Spectrometry; Experimental Geophysics: Investigating Material Properties at Extreme Conditions.

The Liquid Waste Organization (LWO) provided the Savannah River National Laboratory (SRNL) with a Sludge Batch 6 (SB6) composition projection in March 2009. Based on this projection, frit development efforts were undertaken to gain insight into compositional effects on the predicted and measured properties of the glass waste form and to gain insight into frit components that may lead to improved melt rate for SB6-like compositions. A series of Sludge Batch 6 (SB6) based glasses was selected, fabricated and characterized in this study to better understand the ability of frit compositions to accommodate uncertainty in the projected SB6 composition. Acceptable glasses (compositions where the Product Composition Control System (PCCS) Measurement Acceptability Region (MAR) predicted acceptable properties, good chemical durability was measured, and no detrimental nepheline crystallization was observed) can be made using Frit 418 with SB6 over a range of Na{sub 2}O and Al{sub 2}O{sub 3} concentrations. However, the ability to accommodate variation in the sludge composition limits the ability to utilize alternative frits for potential improvements in melt rate. Frit 535, which may offer improvements in melt rate due to its increased B2O3 concentration, produced acceptable glasses with the baseline SB6 composition at waste loadings of 34 and 42%. …

Base Input – Navy Crane Center, Lester, PA discussing the Military value of NCC also including several COBRA print outs.

Research in earth and atmospheric sciences has become increasingly important in light of the energy, climate change, and other environmental issues facing the United States and the world. The development of new energy resources other than fossil hydrocarbons, the safe disposal of nuclear waste and greenhouse gases, and a detailed understanding of the climatic consequences of our energy choices are all critical to meeting energy needs while ensuring environmental safety. The cleanup of underground contamination and the preservation and management of water supplies continue to provide challenges, as they will for generations into the future. To address the critical energy and environmental issues requires continuing advances in our knowledge of Earth systems and our ability to translate that knowledge into new technologies. The fundamental Earth science research common to energy and environmental issues largely involves the physics, chemistry, and biology of fluids in and on the Earth. To manage Earth fluids requires the ability to understand their properties and behavior at the most fundamental molecular level, as well as prediction, characterization, imaging, and manipulation of those fluids and their behavior in real Earth reservoirs. The broad range of disciplinary expertise, the huge range of spatial and time scales, and the …