We investigate the asymmetry of the scattering cross section of radiation around Lyα by atomic hydrogen, which may be applied to analyses of scattering media with high column neutral hydrogen densities including damped Lyα absorption systems of quasars. The exact scattering cross section is given by the Kramers-Heisenberg formula obtained from the fully quantum mechanical second-order time depe...

introduction: the aim of this study was to evaluate the amount of dentine removed after canal preparation using stainless steel (ss) hand instruments or rotary profile instruments. materials and methods: thirty-six extracted human teeth with root canal curvatures less than 30º were embedded in clear polyester resin. the roots were cut horizontally at apical 2, 4 and 7 mm. dentin thickness was m...

the original biophysical profile is time consuming and costly. this study was performed to compare diagnostic value of the original fetal biophysical profile to the modified biophysical profile. patients were selected from high risk pregnancies referred for fetal assessment and were randomly assigned to two groups. the measures of outcomes were perinatal mortality, cesarean section for abnormal...

• Reduced models of solute transport in blood vessels with general velocity fields. Coupled one dimensional flow and transport. The impact axial profiles on the diffusion coefficient. Efficient simulation momentum, vessel area, concentration. main result this paper is formulation derivation a model case profile varying cross section. We couple resulting advection-diffusion equation to reduced f...

Variation elliptical piston skirt has better mechanical and thermodynamic properties and it is widely applied in internal combustion engine in recent years. Because of its complex form, its geometrical precision evaluation is a difficult problem. In this paper, quasi-particle swarm optimization QPSO is proposed to calculate the minimum zone error and ellipticity of crosssection linear profile, ...

The extrusion flow instabilities of commercial polybutadiene (PBD) are investigated as a function the different die geometries, such round capillary, slit, and complex cross-section profile slit dies via capillary rheology. Qualitative models used to fit experimental data for spatial characteristic wavelength (λ) appearing instabilities. A new qualitative model geometry, rectangular cross-secti...