Goertler instability in compressible boundary layers along curved surfaces with suction and cooling

The Goertler instability of the laminar compressible boundary layer flows along concave surfaces is investigated. The linearized disturbance equations for the three-dimensional, counter-rotating streamwise vortices in two-dimensional boundary layers are presented in an orthogonal curvilinear coordinate. The basic approximation of the disturbance equations, that includes the effect of the growth of the boundary layer, is considered and solved numerically. The effect of compressibility on critical stability limits, growth rates, and amplitude ratios of the vortices is evaluated for a range of Mach numbers for 0 to 5. The effect of wall cooling and suction of the boundary layer on the development of Goertler vortices is investigated for different Mach numbers

Nonparallel stability of two-dimensional nonuniformly heated boundary-layer flows

An analysis is presented for the linear stability of water boundary-layer flows over nonuniformly flat plates. Included in the analysis are disturbances due to velocity, pressure, temperatures, density, and transport properties as well as variations of the liquid properties with temperature. The method of multiple scales is used to account for the nonparallelism of the mean flow. In contrast with previous analyses, the nonsimilarity of the mean flow is taken into account. No analysis agrees, even qualitatively, with the experimental data when similar profiles are used. However, both the parallel and nonparallel results qualitatively agree with the experimental results of Strazisar and Reshotko when nonsimilar profiles are used

BcB_c mesons in a Bethe-Salpeter model

We apply our Bethe-Salpeter model for mesons to the $B_c$ family with parameters fixed in our previous investigation. We evaluate the mass of the pseudo-scalar $B_c$ meson as 6.356 GeV/$c^2$ and 6.380 GeV/$c^2$ and the lifetime as 0.47 ps and 0.46 ps respectively in two reductions of the Bethe-Salpeter Equation, in good agreement with the recently reported mass of 6.40 $\pm$ 0.39 (stat.) $\pm$ 0.13 (syst.) GeV/$c^2$ and lifetime of $0.46^{+0.18}_{-0.16}$ (stat.) $\pm$ 0.03 (syst.) ps by the CDF Collaboration. We evaluate the decay constant of the $B_c$ meson and compare different contributions to its decay width.Comment: 9 page

St. Louis limestone, stratigraphy and petrography, near its type locality

The St. Louis Limestone of the Upper Meramecian Series, Mississippian System, is typically lithographic, light-to light-olive gray in color, dense, and fractures conchoidally. It is brecciated, especially in the lower part, and contains some chert nodules. Oolites are present close to the top of the formation. The Salem-St. Louis contact is placed at the base of the lowest breccia zone and the top of Salem is characterized by crystalline quartz and abundance of chert nodules. The appearance of typical Ste. Genevieve oolites with sand-size quartz grains indicates the St. Louis-Ste. Genevieve contact. The St. Louis Limestone is characterized by dominance of fine-grained texture (micritic) with fossil fragments and minor spar. Foraminifers and bryozoans are the main fossil constituents followed by algae, crinoid fragments and corals. Of the corals, Lithostrotionella and Lithostrotion are significant but of less obvious correlative value. Brachiopods and gastropods are present but to a lesser extent. The formation has about 3 to 5 percent insoluble residues (except close to the boundaries), consisting mostly of quartz. The degree of dolomitization is widely variable from one section to another. The St. Louis Limestone is high in CaD content except in the dolomitized zones. The explanation of the origin of brecciation in the St. Louis Limestone presents some difficulty. The St. Louis Limestone is tentatively subdivided into three units. The deposition of limestone was continuous from Salem through St. Louis time under quiet and shallow water environments. In the study area, the St. Louis Limestone is used for cement manufacture and road construction --Abstract, page ii