16,540 research outputs found
Temperature equilibration in a fully ionized plasma: electron-ion mass ratio effects
Brown, Preston, and Singleton (BPS) produced an analytic calculation for
energy exchange processes for a weakly to moderately coupled plasma: the
electron-ion temperature equilibration rate and the charged particle stopping
power. These precise calculations are accurate to leading and next-to-leading
order in the plasma coupling parameter, and to all orders for two-body quantum
scattering within the plasma. Classical molecular dynamics can provide another
approach that can be rigorously implemented. It is therefore useful to compare
the predictions from these two methods, particularly since the former is
theoretically based and the latter numerically. An agreement would provide both
confidence in our theoretical machinery and in the reliability of the computer
simulations. The comparisons can be made cleanly in the purely classical
regime, thereby avoiding the arbitrariness associated with constructing
effective potentials to mock up quantum effects. We present here the classical
limit of the general result for the temperature equilibration rate presented in
BPS. We examine the validity of the m_electron/m_ion --> 0 limit used in BPS to
obtain a very simple analytic evaluation of the long-distance, collective
effects in the background plasma.Comment: 14 pages, 4 figures, small change in titl
Reassessing the History of U.S. Hazardous Waste Disposal Policy - Problem Definition, Expert Knowledge and Agenda-Setting
The authors show that in the 1940\u27s technical consensus began to develop about the effects of land-based waste disposal on groundwater degradation. They go on to explain why this understanding was only slowly reflected in federal legislation
The effects of borrowing rates on intra-firm disequilibria between equity prices and CDS premiums – evidence from dynamic panel analysis.
Cointegration techniques are used to estimate the long run equilibrium relationship between a firm’s CDS premium and its equity price, for a panel of large-cap US firms. From these results, the estimated disequilibrium in daily CDS premiums, with respect to equity prices, is constructed. Dynamic panel methods are employed to show the importance of lagged changes in libor rates as determinants of the estimated disequilibrium. Evidence is found that the extent to which the markets deviate from equilibrium will increase as one-month libor rates rise, but, counter-intuitively, will decrease (return towards equilibrium) as longer term libor rates rise
A Discourse on Diversity: the impact of management team heterogeneity on firm performance.
Quantile models are used to test the association between management team gender, ethnic and educational diversity and firm performance, employing an IV technique developed by Chernozhukov and Hansen (2008) to address the potential endogeneity issues. Estimated associations between measures of diversity and firm EBITDA margins are close to zero across much of the dependent variable distribution, but increase in magnitude for higher margin firms. No evidence of a statistically significant causal relationship between gender and ethnic diversity and firm EBITDA margins is found. Marginal evidence of a statistically significant association between margins and educational diversity is found for high margin firms
Non-Cointegration and Econometric Evaluation of Models of Regional Shift and Share
This paper tests for cointegration between regional output of an industry and national output of the same industry. An equilibrium economic theory is presented to argue for the plausibility of cointegration, however, regional economic forecasting using the shift and share framework often acts as if cointegration does not exist. Data analysis on broad industrial sectors for 20 states finds very little evidence for cointegration. Forecasting models with and without imposing cointegration are than constructed and used to forecast out of sample. The simplest, non-cointegrating models are the best.
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