We show that by using one dimensional anisotropic photonic structures, it is possible to realize optical wave polarization conversion by transmission or by reflection. Thus a single incident S(P) polarized plane wave can produce a single reflected P(S) polarized wave and a single transmitted P(S) polarized wave. This polarization conversion property can be fulfilled with a simple finite superla...

We describe how VSP interferometric imaging of transmitted P-to-S (PS) waves can be used to delineate the flanks of salt bodies. Unlike traditional migration methods, interferometric PS imaging does not require the migration velocity model of the salt or upper sediments in order to image the salt flank. Synthetic elastic examples show that PS interferometric imaging can clearly delineate the up...

In gratings travelling at nearly the velocity of light a symmetry breaking transition is observed between free-flowing fluid-like Bloch waves lower grating velocities and, luminal velocities, condensed, localised states captured in each period and locked to its velocity. We introduce new technique for calculating this regime use it study detail shedding on critical exponents, periodic oscillati...

background: the global burden of sexually transmitted infections (stis) is noticeable and important. however, most stis are curable and all of them are preventable. in this article, we reviewed and evaluated sti prevalence, current services, existing programs, and the challenges of control and management them in iran. materials and methods: the author searched literature published from 2005 to ...

Introduction During hydraulic fracturing experiments in the laboratory the opening of hydraulic fractures is monitored with ultrasonic transducers. The experiment closely resembles seismic monitoring surveys in the field [MEADOWS AND WINTERSTEIN 1994, WILLS ET AL. 1992]. The extraction of information out of these experiments is critically dependent on the understanding of the elastodynamic beha...

Directional hydraulic fracturing method (DHF method) for controlling hard roof in coal mines and the means of its implementation is given paper. The allows getting extended, set a direction cracks stratification cutting off providing their controlled caving different technological schemes. Geo-physical methods are introduced, monitoring mine site experimental testing data on roofs applying extr...