Carbon Nanotube Reinforced Poly(ε-caprolactone)/Epoxy Blends for Superior Mechanical and Self-Sensing Performance in Multiscale Glass Fiber Composites

In this paper, a novel carbon nanotube (CNT) polycaprolactone (PCL), epoxy, and glass fiber (GF) composite is reported. Here, the nanoreinforced composites show a flexural strength increase of around 30%, whereas the interlaminar shear strength increases by 10–15% in comparison to unenhanced samples. This occurs because the addition of the CNTs induces a better PCL/epoxy/GF interaction. Furthermore, the nanoparticles also give novel functionalities to the multiscale composite, such as strain and damage monitoring. Here, the electrical response of the tensile- and compressive-subjected faces was simultaneously measured during flexural tests as well as the transverse conductivity in interlaminar tests, showing an exceptional capability for damage detection. Moreover, it was observed that the electrical sensitivity increases with PCL content due to a higher efficiency of the dispersion process that promotes the creation of a more uniform electrical network.

Positive magnetoresistance induced by hydrodynamic fluctuations in chiral media

We analyze the combined effects of hydrodynamic fluctuations and chiral magnetic effect (CME) for a chiral medium in the presence of a background magnetic field. Based on the recently developed non-equilibrium effective field theory, we show fluctuations give rise to a CME-related positive contribution to magnetoresistance, while the early studies without accounting for the fluctuations find a CME-related negative magnetoresistance. At zero axial relaxation rate, the fluctuations contribute to the transverse conductivity in addition to the longitudinal one.

Поперечная электрическая проводимость и диэлектрическая проницаемость поликристаллического металла

The behavior of a degenerate electron plasma under the action of an alternating transverse electric field of weak intensity is considered. The linearized kinetic equation for electrons in a polycrystalline metal is considered. This kinetic equation takes into account the scattering of electrons at the boundaries of crystallites of a polycrystalline metal. On the basis of this equation, an expression is obtained for the transverse conductivity and transverse dielectric constant of a polycrystalline metal.

Transverse Shubnikov–de Haas effect and the manifestation of quantum diffraction

A quantum diffraction interpretation of the transverse Shubnikov–de Haas effect is presented. Within the framework of the conventional theory of this effect, we show that the matrix element for the electron transition from an initial state to a final state used in calculating the transverse electrical conductivity can be represented as a diffraction-type amplitude distribution. The squared modulus of this matrix element under certain conditions exhibits the Fraunhofer diffraction pattern. It is shown that the oscillating part of the transverse conductivity has the same form as the amplitude for Fraunhofer diffraction by an annular aperture.

Transverse conductivity and the pseudogap in YBCO single crystals irradiated with fast electrons

Temperature dependences of the electrical resistance along the c-axis of [Formula: see text] single crystals are investigated before and after irradiation with electrons at 0.5–2.5 MeV energies. The irradiation was done at [Formula: see text] K and the irradiation dose was varied from [Formula: see text] to [Formula: see text]. An enhancement of the charge carriers localization with increase of the irradiation dose has been revealed. A crossover from the pseudogap (PG) regime to the variable-range hopping conductivity has been observed.

Tailoring anisotropic thermal conductivity by varying filler particle organization in nickel-polydimethylsiloxane composites

Anisotropic properties can be imparted to composite materials by arranging filler particles along specific directions inside the polymer matrix. These anisotropic patterns can be produced through dynamic field-assisted assembly of the filler particles during additive manufacturing. Using finite element analysis, we explore how chainlike arrangements of nickel particles embedded in a polydimethylsiloxane matrix modify bulk thermal conductivities in the axial and transverse directions. The axial conductivity increases up to nine times of the matrix conductivity with increasing filler volume fraction. While the axial conductivity decreases with increasing interparticle spacing, the transverse conductivity is uninfluenced. When particles within a chain are arranged in a zigzag pattern, increasing the interparticle zigzag angle decreases axial conductivity but increases transverse conductivity. As that angle increases to ∼55 º, the axial conductivity approaches a minimum, while the transverse conductivity approaches its maximum. An empirical model that includes effects of interparticle spacing and zigzag angle to predict the anisotropic thermal conductivity of a composite containing particle chains is presented. These results are relevant for the material design of particulate-reinforced polymer composites for advanced field-assisted additive manufacturing strategies.