Model for the conversion of nuclear waste melter feed to glass
The rate of batch-to-glass conversion is a primary concern for the vitrification of nuclear waste, as it directly influences the life cycle of the cleanup process. This study describes the development of an advanced model of the cold cap, which augments the previous model by further developments on the structure and the dynamics of the foam layer. The foam layer on the bottom of the cold cap consists of the primary foam, cavities, and the secondary foam, and forms an interface through which the heat is transferred to the cold cap. Other model enhancements include the behavior of intermediate crystalline phases and the dissolution of quartz particles. The model relates the melting rate to feed properties and melter conditions, such as the molten glass temperature, foaminess of the melt, or the heat fraction supplied to the cold cap from the plenum space. The model correctly predicts a 25% increase in melting rate when changing the alumina source in the melter feed from Al(OH)3 to AlO(OH). It is expected that this model will be incorporated in the full glass melter model as its integral component.
Effect of Gas Percolation on Melting of Glass Batch
A model was developed to predict the temperature distribution, heat transfer, and melting time during unsteady heating and conversion of batch to glass. Percolation of gas through the blanket of batch and heat absorption during the decomposition of carbonates are accounted for in the model. In the glassmelt, heat was assumed to be transferred by combined conduction and radiation. The model equations were solved numerically using a finite-difference method. The effects of several model parameters were investigated. The results of computations show that percolation of gas through the batch increases the time required to convert the batch to glass. Absorption of heat and release of gas in the batch due to decomposition of carbonates changed the temperature distribution in the batchiglass system and the melting times were affected relatively little as long as the total energy absorbed during the transformation process remained unaltered.
American Insurgents, American Patriots: The Revolution of the People
This is a story of rumour, charity, vengeance, and restraint. "American Insurgents, American Patriots" reminds us that revolutions are violent events. They provoke passion and rage, a willingness to use violence to achieve political ends, a deep sense of betrayal, and a strong religious conviction that God expects an oppressed people to defend their rights. The American Revolution was no exception. A few celebrated figures in the Continental Congress do not make for a revolution. It requires tens of thousands of ordinary men and women willing to sacrifice, kill, and be killed. Breen not only tells the history of these ordinary Americans but, drawing upon a wealth of rarely seen documents, restores their primacy to America's road to independence. Mobilizing two years before the Declaration of Independence, American insurgents in all thirteen colonies concluded that resistance to British oppression required organized violence against the state. They channeled popular rage through elected committees of safety and observation, which before 1776 were the heart of American resistance. "American Insurgents, American Patriots" is the stunning account of their insurgency, without which there would have been no independent republic as we know it.