Even during the current biodiversity crisis, reports on population collapses of highly abundant, non-harvested marine species were rare until very recently. This is starting to change, especially at the warm edge of species' distributions where populations are more vulnerable to stress. The Levant basin is the southeastern edge of distribution of most Mediterranean species. Coastal water condit...

In this paper we explore the effect of radiative losses on purely hydrodynamic jet collimation models applicable to Young Stellar Objects (YSOs). In our models aspherical bubbles form from the interaction of a central YSO wind with an aspherical circumprotostellar density distribution. Building on a previous non-radiative study (Frank & Mellema 1996) we demonstrate that supersonic jets are a na...

Pontryagin's principle is used to study the shape of the supersonic part of the nozzle of a carbon dioxide gas-dynamic laser whose gain is maximal. The exact shape is obtained for the uncoupled approximation of Anderson's bimodal model. In this case, if sharp corners are allowed, the ceiling of the supersonic part consists of a slant rectangular sheet followed by a horizontal one; otherwise...

1. Summary Alternative configurations for more efficient supersonic aircraft are suggested by consideration of the sources of drag at high speeds. Results of studies described in this paper indicate that supersonic aircraft with much higher efficiencies than previously achieved are possible with reduced Mach number. The paper focuses on two promising candidate solutions: oblique wings and confi...

[1] The Sun’s open magnetic field, magnetic flux dragged out into the heliosphere by the solar wind, varies by approximately a factor of 2 over the solar cycle. We consider the evolution of open solar flux in terms of a source and loss term. Open solar flux creation is likely to proceed at a rate dependent on the rate of photospheric flux emergence, which can be roughly parameterized by sunspot...

We discuss how the lower corona may be connected to the chromospheric network pattern throughmagnetic funnels at the boundaries of the chromospheric network. At the feet of these funnels are located thin ionizing layers. The steady-state flow and temperature structure in the funnels is analyzed on the basis of the continuity of downward electron heat flux from the coronal base and the upward ad...

A model is developed for the confinement and collimation of a baryon poor outflow by its surrounding medium. Both, confinement by kinetic pressure of a static corona, and confinement by the ram pressure of a supersonic wind emanating from a disk surrounding the inner source are considered. Solutions are presented for the structure of the shocked layers of deflected baryon poor jet (BPJ) and ext...

Rayleigh and Raman scattering measurements have been performed i n the 20-inch, Mach 6 wind tunnel at the NASA Langley Research Center . Rayleigh results show signal levels which are much higher than expected f o r molecular scattering in the tunnel, while densities deduced from s p o n t a n e o u s Raman scattering of molecular nitrogen are in good agreement with t h e expected nitrogen densi...