In the presented work, the author describes a new diagnostic method of ballistic resistance of multi– layered shields. The proper ballistic energy absorbed by the shield is introduced in the form V2BL[R] according to Recht’s and Ipson’s method, and V2BL[Z] according to author’s method. The kinetic energy of the bullet mp · V2p/2 and the momentum of force I are transferred to the shield and the dynamometer of ballistic pendulum. They are used to determine the proper energy V2BL[Z] and ballistic thickness hBL of the shield. The procedure can be widened onto the absorption of the energy by individual layers of the shield, where: AHnan,bn – the effect of n – interlayer on proper energy absorbed by the shield. The effectiveness of the used methods is expressed by average effectiveness coefficient βs of proper energy absorbed by the shield V2BL as well as by average mass coefficients α2s . The ballistic shields can be composed of different grades of metal layers and interlayer areas with well-chosen ballistic proprieties.
The maximization of interlayer effectiveness Nn[R] and Nn[Z] as well as relative mass effectiveness Ms[R] and Ms[Z] leads to optimum conditions of selection of multi–layered shields structures.
Small-scale vertical-axis wind turbines can be used as a source of electricity in rural and urban environments. According to the authors’ knowledge, there are no validated simplified aerodynamic models of these wind turbines, therefore the use of more advanced techniques, such as for example the computational methods for fluid dynamics is justified. The paper contains performance analysis of the small-scale vertical-axis wind turbine with a large solidity. The averaged velocity field and the averaged static pressure distribution around the rotor have been also analyzed. All numerical results presented in this paper are obtained using the SST k-ω turbulence model. Computed power coefficients are in good agreement with the experimental results. A small change in the tip speed ratio significantly affects the velocity field. Obtained velocity fields can be further used as a base for simplified aerodynamic methods.
The purposes of this paper are threefold. The first and the most general purpose is to provide an update of Ingham’s analysis of the southern lexical features that is based on data gathered more than forty years ago (Ingham 1973). On this basis, I will reconsider the lexical link postulated by Ingham (2009: 101, 2007: 577) between the southern gilit-dialects continuum, on the one hand, and the dialects of the Gulf Coast, on the other hand. The second purpose is to reconsider the hitherto maintained lexical frontiers of the southern continuum suggested by Ingham (1994), discussing a range of items that so far have always been treated as ‘southern’, though they are widely spread in other gilit- and, to a less extent, in qeltu-dialects in the western and northern parts of Iraq. The third purpose involves proposing the dichotomy Šrūgi/non-Šrūgi as a new and efficient way of classification of the gilit-dialects. At the end of this paper, a list of Šrūgi lexical features is given.
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