  An effect of sheared large-scale motions on a mean electromotive force in a
nonrotating turbulent flow of a conducting fluid is studied. It is demonstrated
that in a homogeneous divergence-free turbulent flow the alpha-effect does not
exist, however a mean magnetic field can be generated even in a nonrotating
turbulence with an imposed mean velocity shear due to a new ''shear-current"
effect. A contribution to the electromotive force related with the symmetric
parts of the gradient tensor of the mean magnetic field (the kappa-effect) is
found in a nonrotating turbulent flows with a mean shear. The kappa-effect and
turbulent magnetic diffusion reduce the growth rate of the mean magnetic field.
It is shown that a mean magnetic field can be generated when the exponent of
the energy spectrum of the background turbulence (without the mean velocity
shear) is less than 2. The ''shear-current" effect was studied using two
different methods: the Orszag third-order closure procedure and the stochastic
calculus. Astrophysical applications of the obtained results are discussed.
