Keywords: Reaction–diffusion equations Pulsating wave fronts KPP and monostable nonlinearities Uniqueness a b s t r a c t We establish the uniqueness of pulsating wave fronts for reaction–diffusion equations in time periodic media with monostable nonlinearities. For the Kolmogorov–Petrovsky– Piskunov (KPP) type nonlinearity, this result provides a complete classification of all types of KPP pul...

the study of interactions of jet into cross flow at different longitudinal and transverse angles ofjet was studied. the following components were designed and constructed: a low velocity windtunnel to produce the uniform flow, a flat plate with a traverse injection system to simulate the jetinjection, and a spatial rake to measure the total pressure. the tests were carried out atlongitudinal (α...

designing and manufacturing the multiple jets simulator and experimental investigation of the multiple jets in crossflow at low velocity ratios have been studied together with design and build a low-speed wind tunnel. a specific rake is used to determine the flow field pressure and changes in static pressure measured by pressure taps in the near field of the jets. there are generally three regi...

The ventilation flow in the vicinity of the pleopod-pumping thalassinid shrimp Callianassa subterranea in an artificial transparent burrow has been mapped using particle image velocimetry. The flow in the tube in front of the shrimp was unidirectional, laminar and steady, with a parabolic cross-sectional velocity profile. The mean flow velocity was 2.0+/-0.1 mm s-1. The flow passed the thorax o...

We have performed an infrared study of pulsating B stars. The main conclusion is that none of the 163 (non-)radial pulsators shows an IR excess flux due to free-free emission, despite the fact that the sample contains several rapid rotators. Two β Cep stars and two slowly pulsating B stars do exhibit an unexpected infrared colour excess at 12 μm. The small IR excess of the B 2 IV β Cep star HD ...

We present a classification of 267 new variable Btype stars discovered by Hipparcos. We have used two different classification schemes and they both result in only a few new β Cephei stars, a huge number of new slowly pulsating B stars, quite some supergiants with αCyg-type variations and variable CP stars, and further some new periodic Be stars and eclipsing binaries. Our results clearly point...

PURPOSE Retinal venous pulsation detection is a subjective sign, which varies in elevated intracranial pressure, venous obstruction and glaucoma. To date no method can objectively measure and identify pulsating regions. METHOD Using high resolution video-recordings of the optic disk and retina we measured fluctuating light absorption by haemoglobin during pulsation. Pulsation amplitude was ca...

Aims. We test the hypothesis that the pulsations in sdB stars are correlated with the surface abundances of iron-group elements. Any correlation might explain why, when given two spectroscopically similar stars, one will pulsate while the other will not. Methods. We have obtained high-resolution ultraviolet spectra two pulsating and three non-pulsating sdB stars using the Space Telescope Imagin...

One of the world's major mineral dust source regions lies along the border between Iran and Afghanistan. In this studyit is hypothesized that a low-level jet may play in role in generating the intensity of this source region. The presence of alow-level jet east of the Seistan mountains is documented here for the first time. The jet exists mainly from May toSeptember and has a core at 850 mb. Ma...

Numerous investigations have been devoted towards understanding the hydrodynamics of gas jets in fluidized beds. However, most of them address the problem from  macroscopic point of view, which does not reveal the true behavior in the jet region at the single particle level. The present work aims to understand the jet behavior from a more fundamental level, i.e. the individual particle leve...