Publications by authors named "S Ponomarenko"

To achieve the actuation of silicone-based foamed composites, a liquid-gas phase transition of the liquid captured in its pores is employed. The uncertainty of key parameters for a single or sequential open-air performance of such soft actuators limits their application. To define the main characteristics of the composites, in this work, two functions of the liquid there were separated: the pore-forming agent (FPA) and working liquid (WL).

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The hypothesis that the antibacterial effect of copper depends on its state was tested. It was studied the antibacterial effect of copper applied to the fabric, copper in chelated and free (ionic) forms on the growth intensity of and in the system after a single or "primary" contact. Classical microbiology methods were used.

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We discover a connection between a Gauss sum of number theory and the degree of coherence (DOC) of the field in a transverse plane of structured speckled light beams. We theoretically demonstrate and experimentally validate that prime number factorization can be achieved by manipulating the source beam's DOC in Young's double-slit experiment. The determination of whether a number can be factored is based solely on the visibility of the resulting interference patterns.

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We introduce perfect correlation vortices and show that the degree of coherence of any such vortex at the source is nearly statistically homogeneous and independent of the topological charge of the vortex. We demonstrate that while slowly diffracting in free space, perfect correlation vortices maintain their "perfect" vortex structure; they are capable of preserving said structure even in strong atmospheric turbulence. Structural resilience to diffraction and turbulence sets the discovered perfect vortices apart from their coherent cousins and makes them suitable for free-space optical communications.

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We introduce the concept of perfect space-time vortices (PSTVs) that can exist in media with anomalous dispersion. If the topological charge of a PSTV is not too large, the spatiotemporal intensity distribution of the vortex field does not depend on the magnitude of the topological charge. We show theoretically how a PSTV can be realized in the optical context through spatiotemporal focusing of a Bessel-Gaussian space-time optical vortex source that is placed in the focal plane of a space-time lens composed of an ordinary lens and a time lens with matched spatial and temporal focal lengths.

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