On the Influence of Stochastic Moments in the Solution of the Neutron Point Kinetics Equation

On the Influence of Stochastic Moments in the Solution of the Neutron Point Kinetics EquationComment: 12 pages, 2 figure

Comment on "Long-range electrostatic interactions between like-charged colloids: Steric and confinement effects"

In a recent study [Phys. Rev. E 60, 6530 (1999)], Trizac and Raimbault showed that the effective pair interaction between like charged colloids immersed in a cylindrically confined electrolyte remains repulsive even when the size of the micro-ions or the finite longitudinal extension of the confining cylinder are taken into account. Contrary to their claim, we argue that the case of finite longitudinal confinement doesn't always generate repulsive interactions and to illustrate this point we also provide a simple example.Comment: 3 pages, 1 figure. Accepted for publication in Phys. Rev. E 200

Application of time-dependent density functional theory to optical activity

As part of a general study of the time-dependent local density approximation (TDLDA), we here report calculations of optical activity of chiral molecules. The theory automatically satisfies sum rules and the Kramers-Kronig relation between circular dichroism and optical rotatory power. We find that the theory describes the measured circular dichroism of the lowest states in methyloxirane with an accuracy of about a factor of two. In the chiral fullerene C_76 the TDLDA provides a consistent description of the optical absorption spectrum, the circular dichroism spectrum, and the optical rotatory power, except for an overall shift of the theoretical spectrum.Comment: 17 pages and 13 PostScript figure

Pressure dependence of diffusion coefficient and orientational relaxation time for acetonitrile and methanol in water: DRISM/mode-coupling study

We present results of theoretical description and numerical calculation of the dynamics of molecular liquids based on the Reference Interaction Site Model / Mode-Coupling Theory. They include the temperature-pressure(density) dependence of the translational diffusion coefficients and orientational relaxation times for acetonitrile and methanol in water at infinite dilution. Anomalous behavior, i.e. the increase in mobility with density, is observed for the orientational relaxation time of methanol, while acetonitrile does not show any deviations from the usual. This effect is in qualitative agreement with the recent data of MD simulation and with experimental measurements, which tells us that presented theory is a good candidate to explain such kind of anomalies from the microscopical point of view and with the connection to the structure of the molecules.Comment: 10 pages, 2 eps-figures, 3 table

Evaluation and histological examination of a Campylobacter fetus subsp. venerealis small animal infection model

Bovine genital campylobacteriosis (BGC), caused by Campylobacter fetus subsp. venerealis, is associated with production losses in cattle worldwide. This study aimed to develop a reliable BGC guinea pig model to facilitate future studies of pathogenicity, abortion mechanisms and vaccine efficacy. Seven groups of five pregnant guinea pigs (1 control per group) were inoculated with one of three strains via intra-peritoneal (IP) or intra-vaginal routes. Samples were examined using culture, PCR and histology. Abortions ranged from 0% to 100% and re-isolation of causative bacteria from sampled sites varied with strain, dose of bacteria and time to abortion. Histology indicated metritis and placentitis, suggesting that the bacteria induce inflammation, placental detachment and subsequent abortion. Variation of virulence between strains was observed and determined by culture and abortion rates. IP administration of C. fetus subsp. venerealis to pregnant guinea pigs is a promising small animal model for the investigation of BGC abortion

Dirac Equation Studies in the Tunnelling Energy Zone

We investigate the tunnelling zone V0 < E < V0+m for a one-dimensional potential within the Dirac equation. We find the appearance of superluminal transit times akin to the Hartman effect.Comment: 12 pages, 4 figure

Исследование температурного поля пневматического молотка

Представлены результаты экспериментального исследования изменения температуры поверхности рубильного пневматического молотка М-6 по времени при рубке в различных режимах стальной полосы и плиты, чугунной плиты