Models of ballistic propagation of heat at low temperatures

Heat conduction at low temperatures show various effects that cannot be described by the Fourier law, like the second sound and ballistic propagation. In this paper the performance of various theories is compared in case of ballistic and wave like propagation of heat pulses in NaF

Monte Carlo simulation of the electrical properties of electrolytes adsorbed in charged slit-systems

We study the adsorption of primitive model electrolytes into a layered slit system using grand canonical Monte Carlo simulations. The slit system contains a series of charged membranes. The ions are forbidden from the membranes, while they are allowed to be adsorbed into the slits between the membranes. We focus on the electrical properties of the slit system. We show concentration, charge, electric field, and electrical potential profiles. We show that the potential difference between the slit system and the bulk phase is mainly due to the double layers formed at the boundaries of the slit system, but polarization of external slits also contributes to the potential drop. We demonstrate that the electrical work necessary to bring an ion into the slit system can be studied only if we simulate the slit together with the bulk phases in one single simulation cell.Comment: 11 pages, 8 figure

Empirical relations for cluster RR Lyrae stars revisited

Our former study on the empirical relations between the Fourier parameters of the light curves of the fundamental mode RR Lyrae stars and their basic stellar parameters has been extended to considerably larger data sets. The most significant contribution to the absolute magnitude M_v comes from the period P and from the first Fourier amplitude A_1, but there are statistically significant contributions also from additional higher order components, most importantly from A_3 and in a lesser degree from the Fourier phase phi_51. When different colors are combined in reddening-free quantities, we obtain basically period-luminosity-color relations. Due to the log T_eff (B-V, log g, [Fe/H]) relation from stellar atmosphere models, we would expect some dependence also on phi_31. Unfortunately, the data are still not extensive and accurate enough to decipher clearly the small effect of this Fourier phase. However, with the aid of more accurate multicolor data on field variables, we show that this Fourier phase should be present either in V-I or in B-V or in both. From the standard deviations of the various regressions, an upper limit can be obtained on the overall inhomogeneity of the reddening in the individual clusters. This yields sigma_E(B-V)}< 0.012 mag, which also implies an average minimum observational error of sigma_V > 0.018 mag.Comment: 14 pages, 11 figures, 11 tables, accepted in Astronomy & Astrophysic

The effect of companion planting on the abundance of pest complex and its parasitism rate on white cabbage

The findings of this paper could help to develop and maintain a sustainable cabbage production by the enhancement of natural pest control with the help of companion planting. Our results indicate that Lobularia maritima (Brassicaceae) could be used to attract pests of cruciferous plants away from the crop. Centaurea cyanus (Asteraceae) and Fagopyrum esculentum (Polygonaceae) could be used to suppress pests of cruciferous crops and to increase parasitism rate by fostering parasitoids