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It is shown that if the entropy current may depend only on the currents and the equilibrium state variables then only the formula corresponding to Gibbs's relation is acceptable. All other formulae of this type lead to (physical) contradiction.If, however, nothing is assumed about the coefficients of the extensive quantity currents in the formula of the entropy current then we get an extra set of constitutive equations for these coefficient tensors. These second order tensors play the role of intensive quantities: their divergences are the thermodynamical forces conjugated to the currents, while their deviation from the equilibrium intensive quantities is induced by the current gradients. Thus, a nonequilibrium entropy current, converging to the classical equilibrium one as approaching equilibrium, is obtained.This theory applied to conductive energy transport contains a second order tensor playing a role similar to reciprocal temperature. The heat transport equation obtained after eliminating this tensor from the equations contains an extra term. This modified "heat conduction" equation is identical to the classical one in stationary state, while its dynamic behavior predicts a characteristic length and time, both vanishing with the coefficient of the extra term.The theory permits coupling between viscous flow and conductive energy transport even in linear order.

The thermal conductivity and shear viscosity of the three-dimensional classical one-component plasma ͑OCP͒ were determined by molecular dynamics experiments. In the simulations the velocity of the particles was spatially modulated, and the transport coefficients were calculated from the relaxation time of the modulation profile. The results are given for the 2р⌫р125 range of the plasma coupling parameter ⌫. The reduced shear viscosity * was found to exhibit a minimum at ⌫ϭ20 in agreement with previous calculations. In the 2р⌫р10 range our method yields * values 20%-50% higher compared to some of the previously obtained data, while very good agreement was found at the position of the minimum of *. The reduced thermal conductivity * exhibits a minimum ͑similarly to *) at ⌫ between 15 and 20. The calculations presented here result in 30%-40% lower thermal conductivity compared to previously available data.

The treatment couch is not radio-transparent. Its presence between the patient and beam source significantly alters dose in the patient. For the most part, a modern treatment planning system can adequately predict the altered dose distribution.

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We carried out molecular dynamics experiments to determine the reduced heat diffusion coefficient D ‫ء‬ th and the reduced thermal conductivity l ‫ء‬ of the three-dimensional classical electron one-component plasma, for the 1 # G # 20 range of the plasma coupling parameter G. In our simulations the temperature of the system was spatially modulated, and D ‫ء‬ th and l ‫ء‬ were calculated from the relaxation time of the temperature profile. D ‫ء‬ th was found to decrease with increasing G, while l ‫ء‬ decreased with increasing G for G # 4 (from l ‫ء‬ Х 2.3 at G 1.1 to l ‫ء‬ Х 0.6 at G 4) and was approximately constant (l ‫ء‬ Х 0.4) in the 8 # G # 20 range. [S0031-9007(98)06853-7]

The methods described provide a quantitative measure of beam spot position, are easy to use, and provide another tool for Linac setup and quality assurance. Fundamental to the techniques is that they are self-referencing-i.e., they do not require the user to independently define the CAOR.

Recent findings in populations exposed to ionizing radiation (IR) indicate dose-related lens opacification occurs at much lower doses (<2 Gy) than indicated in radiation protection guidelines. As a result, research efforts are now being directed towards identifying early predictors of lens degeneration resulting in cataractogenesis. In this study, Raman micro-spectroscopy was used to investigate the effects of varying doses of radiation, ranging from 0.01 Gy to 5 Gy, on human lens epithelial (HLE) cells which were chemically fixed 24 h post-irradiation. Raman spectra were acquired from the nucleus and cytoplasm of the HLE cells. Spectra were collected from points in a 3  ×  3 grid pattern and then averaged. The raw spectra were preprocessed and principal component analysis followed by linear discriminant analysis was used to discriminate between dose and control for 0.25, 0.5, 2, and 5 Gy. Using leave-one-out cross-validation accuracies of greater than 74% were attained for each dose/control combination. The ultra-low doses 0.01 and 0.05 Gy were included in an analysis of band intensities for Raman bands found to be significant in the linear discrimination, and an induced repair model survival curve was fit to a band-difference-ratio plot of this data, suggesting HLE cells undergo a nonlinear response to low-doses of IR. A survival curve was also fit to clonogenic assay data done on the irradiated HLE cells, showing a similar nonlinear response.