Dense Behavior Research Articles

Charged anisotropic strange stars in $f(\mathcal{G})$ gravity

This paper examines the charged anisotropic strange stars by employing the embedding class-1 condition in the framework of $f(\mathcal{G})$ gravity. For this reason, we use MIT bag model to derive the expression of charge inside the geometry. We evaluate the unknown constants by the matching of interior spacetime with the Riessner-Nordstrom geometry. The radii are predicted for the star models like Vela X-1, 4U 1608-52, LMC X-4 and PSR J0348+0432 by using their observed masses. We check the viability and stability of the resulting solution through graphical behavior of matter components, energy constraints, adiabatic index and causality condition. It is observed that strange stars exhibit more dense behavior in the presence of charge and MIT bag model. We conclude that embedding class-1 solution shows viable and stable behavior for charged anisotropic strange stars in this theory.

High-Rate and Large-Capacity Lithium Metal Anode Enabled by Volume Conformal and Self-Healable Composite Polymer Electrolyte.

The widespread implementation of lithium‐metal batteries (LMBs) with Li metal anodes of high energy density has long been prevented due to the safety concern of dendrite‐related failure. Here a solid–liquid hybrid electrolyte consisting of composite polymer electrolyte (CPE) soaked with liquid electrolyte is reported. The CPE membrane composes of self‐healing polymer and Li+‐conducting nanoparticles. The electrodeposited lithium metal in a uniform, smooth, and dense behavior is achieved using a hybrid electrolyte, rather than dendritic and pulverized structure for a conventional separator. The Li foil symmetric cells can deliver remarkable cycling performance at ultrahigh current density up to 20 mA cm−2 with an extremely low voltage hysteresis over 1500 cycles. A large areal capacity of 10 mAh cm−2 at 10 mA cm−2 could also be obtained. Furthermore, the Li|Li4Ti5O12 cells based on the hybrid electrolyte achieve a higher specific capacity and longer cycling life than those using conventional separators. The superior performances are mainly attributed to strong adhesion, volume conformity, and self‐healing functionality of CPE, providing a novel approach and a significant step toward cost‐effective and large‐scalable LMBs.

New applications of the flash method

Two methods for measuring the thermal diffusivity of semitransparent solid ceramics and ceramic coatings on metallic substrates are described. Tests conducted on various zirconias have shown these materials to be highly unstable and tend to show that such materials exhibit an optically dense behaviour at high temperature. The use of a phosphate glass Q-switched laser with very short pulse (25 ns) allows the characterisation of a thin coating of ceramic with thickness between 15 and 50 μm. A new method for measuring the thermal diffusivity in the three principal directions of a three-dimensional composite material is described. The principle is derived from the flash method. It consists of heterogeneously illuminating one of the faces of a square-base specimen (by two parallel bands) in order to analyse heat transfer in the parallel direction (x and y directions) and the perpendicular direction (z direction) of the faces of the specimen. An example of a result obtained on anisotropic graphite demonstrates the validity of the method. This method applied to a homogeneous material gives two thermal diffusivity values (α x and α y ), thereby improving the measurement accuracy and reliability.