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• Jet fuel is the fastest-growing oil-based commodity. • Hydrotreated esters and fatty acids (HEFA), kerosene from hydrocracking (Jet HC) and FCC heavy naphtha (FCC HN) were researched. • The blendability of HEFA with Jet HC and with FCC HN was determined to meet the specification of JET A-1. • The results can help increase the production of jet fuel in oil refineries. Jet fuel is the fastest-growing oil-based commodity. As it is difficult to substitute it with other energies, more attention is being paid to sustainable aviation fuels (SAFs). Hydrogenated esters and fatty acids (HEFAs) dominate SAF now. The jet fuel consumption forecasts show that the share of petroleum hydrocarbons in jet fuel will remain high until 2050. As oil consumption will decline with electromobility, the availability of straight-run kerosene for jet fuel will also decline. For this reason, the utilization of alternative petroleum fractions, such as hydrocracking kerosene (Jet HC) or hydrotreated heavy FCC naphtha (FCC HN), and their miscibility with HEFA have been studied. These components were generally blendable with HEFA. All properties were linearly dependent on the HEFA content, with the exception of the smoke point. Taking into account the Jet A-1 requirements, only Jet HC met them completely. Since the components have opposing properties, blending them has opened an application window in jet fuel, wider for blends of HEFA with Jet HC (0–68 vol% HEFA) and narrower for HEFA with FCC HN (73–81 vol% HEFA). The limitations were the low density of HEFA and the high density, the high aromatic content, the low smoke point, and the low net calorific value of FCC HN. To expand the application window of FCC HN in jet fuel, further research will focus on the hydrogenation of aromatics. [ABSTRACT FROM AUTHOR]

Thickening of structured acrylate latices with butyl acrylate/styrene/2-hydroxyethyl methacrylate/acrylic acid copolymer showed that association of the thickener based on hydrophobically modified ethoxylated polyurethane (HEUR) with the latex particles was considerably affected by hydrophobicity of the particle shell surface controlled by various content of styrene units in the copolymer. In contrast, the thickening mechanism of hydrophobically modified alkali-soluble emulsion (HASE) and, consequently, the viscosity of thickened materials depends predominantly on the excluded volume of swollen thickener particles and the influence of the styrene content is negligible. [Copyright &y& Elsevier]

Charged perfect fluid with vanishing Lorentz force and massless scalar field is studied for the case of stationary cylindrically symmetric spacetime. The scalar field can depend both on radial and longitudinal coordinates. Solutions are found and classified according to scalar field gradient and magnetic field relationship. Their physical and geometrical properties are examined and discussion of particular cases, directly generalizing Gödel-type spacetimes, is presented. [ABSTRACT FROM AUTHOR]

For the plane symmetry we have found the electro-vacuum exact solutions of the Einstein-Maxwell equations and we have shown that one of them is equivalent to the McVittie solution of a charged infinite thin plane. The analytical extension has been accomplished and the Penrose conformal diagram has been obtained as well. [ABSTRACT FROM AUTHOR]

For stationary cylindrically symmetric solutions of the Einstein-Maxwell equation we have shown that the “charged” solutions of McCrea, Chitre et al. (CGN), Van den Bergh and Wils (VW) can be obtained from the seed metrics using generating conjecture. The McCrea “charged” solution has as a seed vacuum metric the Van Stockum solution with a Killing vector (0, 0, 1, 0). The CGN “charged” solution and the VW “charged” solution have the static seed metrics connected by the complex substitution t → i z, z → i t and the Killing vector which is a simple linear combination of ∂ ϕ and ∂ t Killing vectors (VW), respectively ∂ ϕ and ∂ z Killing vectors (CGN). [ABSTRACT FROM AUTHOR]

The method based on the Horský-Mitskievitch conjecture is applied to the Levi-Civita vacuum metric. It is shown, that every Killing vector is connected with a particular class of Einstein-Maxwell fields and each of those classes is found explicitly. Some of the obtained classes are quite new. Radial geodesic motion in constructed space-times is discussed and graphically illustrated in the Appendix. [ABSTRACT FROM AUTHOR]

Abstract: The rheological study of acrylate latices showed that an important factor influencing thickening with hydrophobically ethoxylated urethane (HEUR) associative thickeners is the effective hydrodynamic volume of latex particles, which in concentrated latices controls the remaining volume available for the thickener macromolecules. Thus, the larger volume corresponding to a smaller size of alkalinized swollen particles of ethyl acrylate/acrylic acid copolymers with “hard” comonomers methyl methacrylate or styrene leads to lower density of network structure of the thickener bridging the latex particles and, consequently, to lower viscoelasticity of the thickened material. [Copyright &y& Elsevier]