Group A streptococci (GAS) cause three different types of infection (sensu lato) with distinct levels of virulence: asymptomatic colonization, superficial symptomatic infection, and invasive infection. To address why this pattern with several infection types has evolved, we combine mechanistic understanding from infection medicine with recent theory from evolutionary ecology. We propose that as...

Oxygen transport resistance at the air flow channel and gas diffusion layer (GDL) interface is needed in modelling the performance of a proton exchange membrane fuel cell (PEMFC). This resistance is expressed through the non-dimensional Sherwood number (Sh). The effect of the presence of a droplet on Sh is studied numerically in an isolated air flow channel using a commercially available packag...

We have obtained integral-field spectroscopic data, using the SAURON instrument, of the bar and starbursting circumnuclear region in the barred spiral galaxy M100. From our data we have derived kinematic maps of the mean velocity and velocity dispersion of the stars and the gas, which we present here. We have also produced maps of the total, [Oiii], and Hβ intensity. The gas velocity field show...

Foam fractionation is one of the low operating-cost techniques for removing proteins from a dilute solution. The initial bulk solution pH and air superficial velocity play an important role in the foam-fractionation process. Denaturation of proteins (enzymes) can occur, however, during the foam-fractionation process from the shear forces resulting from bursting air bubbles. At the extreme bulk ...

in this paper, direct numerical simulation of two-phase incompressible gas-liquid flow for simulation of bubble motion in a microtube is presented. microtube radius is 10 µm. the interface is tracked using volume of fluid (vof) method with continuous surface force (csf) model. the flow is solved using a finite volume scheme, based on piso algorithm. numerical simulation is performed on a axisym...

Macroscopic slip velocity, macroscopic temperature jump, thermal creep velocity and diffusion slip velocity for a mixture of monatomic gases are calculated by using a method developed recently (modified Maxwell-method) for a general gas-gas and gas-surface interaction law, and for a possibly anisotropic surface. The results are expressed in terms of accommodation coefficients of first and secon...

composite pressure vessel cng made of epoxy – carbon material with nonmetal liner is 60% lighter than aluminum vessel under the same conditions. one of the important parameters in the pressure vessels design is their resistance against impact and prevention of explosion. in this paper, the effects of low velocity impact on composite pressure vessel are investigated using fe analysis. the vessel...

Objectives To investigate the mechanical responses of microdefect articular cartilage under rolling load and find out the failure rule. Methods Rolling load was applied to the porcine articular cartilage samples with rectangular notches of different depths. The displacement and strain near the notches were obtained by the noncontact digital image correlation technique. Results The strain va...