Shear-free Perfect Fluids in General Relativity: Gravito-magnetic Spacetimes

We investigate shear-free, perfect fluid solutions of Einstein's field equations in which the perfect fluid satisfies a barotropic equation of state p = p(w) such that w + p 0. We find that if the electric part of the Weyl tensor (with respect to the fluid flow) vanishes and the spacetime is not conformally flat then the fluid volume expansion is zero but the vorticity is necessarily nonzero. In addition, we show that if p = –w/3 then necessarily either the fluid expansion is zero or the fluid vorticity is zero.     

Application of Oil-in-Water Nanoemulsion Carrying Size-Defined Gold Nanoparticles Synthesized by Non-thermal Plasma for the Human Breast Cancer Cell Lines Migration and Apoptosis

Plasma Chemistry and Plasma Processing - In this work, the gold nanoparticles (AuNPs) were synthesized using pulse-modulated radio-frequency atmospheric pressure glow discharge (pm-rf-APGD). By...     

New Core-Shell Type Polymeric Supports Based on the Amberlite XAD-4 Adsorbent: A Novel Synthesis Procedure

The chloromethyl groups have been introduced into commercial S/DVB copolymer matrixes via interpenetrating polymer networks (IPN) synthesis. The procedure involves impregnation of the Amberlite XAD‐4 adsorbent, with use of the vinylbenzyl chloride (VBC) and divinylbenzene (DVB) monomers mixture, and suspension polymerization process. The syntheses were evaluated by FT‐IR spectra and SEM analyses and furthermore by chlorine content determination as well as characterization of porous structure by nitrogen adsorption at liquid nitrogen temperature. Designed synthesis approach allowed determining organic and water phases composition. Furthermore, impact of an excess of the organic phase removal method has been investigated. Basing on the obtained results it could be stated that the chloromethyl groups, derived from VBC monomer, were successfully introduced into the XAD‐4 structure. Captured SEM images revealed significant changes in the beads' surface morphology after polymerization processes. The presented studies reveal designed and executed synthesis processes, which involve the use of a proper water phase and excess of organic phase removal. Observed changes in the beads' morphology suggest that introduced functionalities are concentrated on the porous surface of the XAD‐4 adsorbent.