We investigate the linear stability of unstably strati ed Poiseuille ow between two horizontal parallel plates under non-Boussinesq conditions. It is shown, that Squire's transformation can be used to reduce the three-dimensional stability problem to an equivalent two-dimensional one. The eigenvalue problem, consisting of the generalized Orr-Sommerfeld equations, is solved numerically using an ...

The parallel implementation of GCR is addressed, with particular focus on communication costs associated with orthogonalization processes. This consideration brings up questions concerning the use of Householder reflections with GCR. To precondition the GCR method a block Gauss-Jacobi method is used. Approximate solvers are used to obtain a solution of the diagonal blocks. Experiments on a clus...

An angular spectrum model for predicting the transformation of Stokes waves on a mildly varying topography is developed, including refraction, diffraction, shoaling and nonlinear wave interactions. The equations governing the water-wave motion are perturbed using the method of multiple scales and Stokes expansions for the velocity potential and free-surface displacement. The first-order solutio...

one of the important technical obstacles in the study of many filamentous fungi is the development of efficient transformation system. transformation of filamentous fungi is difficult because they have a cell wall and for most frequently used approaches preparing of protoplast is necessary. protoplast preparation is batch-dependent and often frustrating work. in this study, a modified method wa...

geospatial information system (gis) has emerged as a very powerful tool for capturing, storing, analyzing, managing, and presenting data that is linked to location. the location information, which is usually obtained from existing maps or the global positioning systems (gps), refers to different coordinate and map projection systems. therefore, unification of the coordinate and mapping systems ...

A mixed spectral method is proposed and analyzed for the Stokes problem in a semi-infinite channel. The method is based on a generalized Galerkin approximation with Laguerre functions in the x direction and Legendre polynomials in the y direction. The well-posedness of this method is established by deriving a lower bound on the inf-sup constant. Numerical results indicate that the derived lower...

In this paper, a systematic, overall view of theories for periodic waves of permanent form, such as Stokes and cnoidal waves, is described first with their validity ranges. To deal with random waves, a method for estimating directional spectra is given. Then, various wave equations are introduced according to the assumptions included in their derivations. The mild-slope equation is derived for ...

We present the two-scale-transformation method which allows rigorous homogenisation of problems defined in locally periodic domains. This transforms such into domains order to facilitate passage limit. The idea transforming originates from evolving microstructure and has been applied several works. However, only substitute was proven, whereas itself just postulated (i.e. equivalence actual prob...