Thoughts of agoraphobic people during scary tasks.

The authors examined the occurrence of theoretically derived patterns of thinking in 74 agoraphobic participants as they drove alone or tolerated an enclosed place. During the increasingly scary tasks in a behavioral test hierarchy, participants responded to a periodic beep by stating aloud what they were thinking at that moment, yielding more than 1,800 tape-recorded statements. Content analyses revealed that participants were mainly preoccupied with their current anxiety (expressed in 29% of the statements) and with their self-efficacy (15%). Despite participants' mounting feelings of anxiety, fewer than 1% of their statements expressed a thought of danger or an anticipation of future anxiety or panic. The rarity of danger thoughts poses an explanatory challenge for all cognitive theories of phobia and especially for the perceived danger theory of A. T. Beck (1976) and A. T. Beck, G. Emery, and R L. Greenberg (1985). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lean NOx Trap Chemistry Under Lean-Gasoline Exhaust Conditions: Impact of High NOx Concentrations and High Temperature

The primary technical barrier to deployment of fuel saving lean gasoline engines is NOx emissions control. We conducted automated flow reactor experiments on a commercial LNT catalyst to identify opportunities and challenges associated with the higher temperatures and higher NOx concentrations expected in lean gasoline applications. Overall NOx conversion was quite high at low to moderate temperatures, but dropped off at high temperatures. The decrease in NOx conversion with temperature was worse for higher inlet NOx concentrations. As expected from equilibrium considerations, the catalyst stored more NOx under higher gas phase NOx concentrations, but that NOx was rapidly released during the rich phase and slipped out of the catalyst before it could be converted to N₂ by incoming reductant. This rich phase NOx release was the primary factor limiting performance of the catalyst at high temperatures, and resulted in significant spikes of NOx that would likely exceed any not-to-exceed regulated emissions levels. N₂O production was also significant, and increased with NOx concentration. The catalyst made very little NH₃ at high temperatures. NH₃ yield was significant at the lowest operating temperature studied, but it decreased with increasing NOx concentration.     

Crossflow filtration testing of INEEL radioactive and non-radioactive waste slurries

Development of waste treatment processes for the remediation of radioactive wastes is currently under way at the Idaho Nuclear Technology and Engineering Center (INTEC), located at the Idaho National Engineering and Environmental Laboratory (INEEL). INTEC, formerly known as the Idaho Chemical Processing Plant, previously reprocessed nuclear fuel to retrieve fissionable uranium. Liquid waste raffinates resulting from reprocessing were solidified into a calcine material. Waste treatment processes currently being considered include the dissolution of the solidified calcine material and separation of residual undissolved solids (UDS). UDS in solution must be removed prior to downstream processes such as solvent extraction and ion exchange. Filtration experiments were conducted at the INEEL using a crossflow filter apparatus on radioactive and non-radioactive waste slurries [N.R. Mann, T.A. Todd, Evaluation and Testing of the Cells Units Crossflow Filter on INEEL Dissolved Calcine Slurries, INEEL/EXT-98-00749, Idaho National Engineering and Environmental Laboratory, Idaho Falls, ID, 1998]. The purpose of this testing was to evaluate the removal and operational efficiency of crossflow filtration on slurries of various solids loadings. The solids loadings tested were 0.19, 2.44 and 7.94 wt.%, respectively. A matrix of test patterns was used to determine the effects of transmembrane pressure and axial velocity on filtrate flux. Filtrate flux rates for each solids loading displayed a high dependence on transmembrane pressure, indicating that pressure filtration resistance limits filtrate flux. Filtrate flux rates for all solids loading displayed a negative dependency on axial velocity. This would suggest axial velocities tested were efficient at removing filter cake. Prior to testing of actual waste slurries, baseline water runs were performed. Filtrate flowrates observed during baseline water runs exhibited substantial decreases despite numerous backpulses and rinses, suggesting particles that were deeply embedded within the filter membrane as the result of shear-induced deagglomeration     

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