This paper deals with violent discontinuities in shallow water flows with large Froude number F . On a horizontal base, the paradigm problem is that of the impact of two fluid layers in situations where the flow can be modelled as two smooth regions joined by a singularity in the flow field. Within the framework of shallow water theory we show that, over a certain timescale, this discontinuity ...

In low-collisionality plasmas, anisotropic heat conduction due to a magnetic field leads to buoyancy instabilities for any nonzero temperature gradient. We study analogous instabilities in degenerate collisional plasmas, i.e., when the electron collision frequency is large compared to the electron cyclotron frequency. Although heat conduction is nearly isotropic in this limit, the small residua...

The rise of the periphrastic future (PF) at the expense of the inflected future (IF) is an established historical trend in Québécois French over at least the past 150 years. Previous research has also found higher rates of PF among younger speakers, many displaying categorical use in affirmative contexts. Because an apparent time interpretation of the synchronic data fits the historical record,...

Abstract Thermospheric waves occurring around the time of the 14 July 2000 solar flare were investigated using the Global Ionosphere and Thermosphere Model. The simulation results showed that extensive acoustic and gravity waves were excited by the solar flare in the subsolar region. The subsolar buoyancy period at 400 km altitude was approximately 16 min. Gravity waves with frequencies lower t...

This paper presents the results of a numerical study that examines the surface heating discrepancies observed between computed and measured values along a sharp cone. With Mach numbers of an order of 10 and the free-stream length Reynolds number of an order of 10 000, the present computations have been made with the direct simulation Monte Carlo (DSMC) method by using the G2 code of Bird. The o...

The approximate method for the account of compressibility, which was successfully applied earlier for 2-D problems, is developed for axisymmetric case in the present work. The offered method is analyzed with reference to two mediums: air and water. Comparison of the results of calculations on an offered method and a method of Dorodnitsyn integrate relations has shown acceptable accuracy of the ...

Determining species distributions accurately is crucial to developing conservation and management strategies for imperiled species, but a challenging task for small populations. We evaluated the efficacy of environmental DNA (eDNA) analysis for improving detection and thus potentially refining the known distribution of Chinook salmon (Oncorhynchus tshawytscha) in the Methow and Okanogan Subbasi...