Cold-Field Switching in PVDF-TrFE Ferroelectric Polymer Nanomesas

Polarization reversal in ferroelectric nanomesas of polyvinylidene fluoride with trifluoroethylene has been probed by ultrahigh vacuum piezoresponse force microscopy in a wide temperature range from 89 to 326 K. In dramatic contrast to the macroscopic data, the piezoresponse force microscopy local switching was nonthermally activated and, at the same time, occurring at electric fields significantly lower than the intrinsic switching threshold. A "cold-field'' defect-mediated extrinsic switching is shown to be an adequate scenario describing this peculiar switching behavior. The extrinsic character of the observed polarization reversal suggests that there is no fundamental bar for lowering the coercive field in ferroelectric polymer nanostructures, which is of importance for their applications in functional electronics

Research of long-term properties of high-strength fiberglasses by means of the built-in FBG sensors

In this work the possibility of use of the built-in fiber-optical sensors (Bragg's sensors) of deformation for control of a condition of polymeric fiberglasses on epoxy polymer matrix ED-I cured at the increased temperature was investigated. Sensors were inserted in different layers of the layered plastic reinforced by biaxial fiber glass fabric. The package of layers had quasiisotropic structure. The sample made by method of vacuum impregnation was affected by saturated steam (90 °C) within 6 months. Operability of system of measurement has been as a result shown and swelling parameters in different layers of FGRP were recorded. For measurement measuring systems of two types — on a superbright light-emitting diode and on the tunable laser were used

Research of long-term properties of high-strength fiberglasses by means of the built-in FBG sensors

In this work the possibility of use of the built-in fiber-optical sensors (Bragg's sensors) of deformation for control of a condition of polymeric fiberglasses on epoxy polymer matrix ED-I cured at the increased temperature was investigated. Sensors were inserted in different layers of the layered plastic reinforced by biaxial fiber glass fabric. The package of layers had quasiisotropic structure. The sample made by method of vacuum impregnation was affected by saturated steam (90 °C) within 6 months. Operability of system of measurement has been as a result shown and swelling parameters in different layers of FGRP were recorded. For measurement measuring systems of two types — on a superbright light-emitting diode and on the tunable laser were used

Human monkeypox and smallpox viruses: genomic comparison

AbstractMonkeypox virus (MPV) causes a human disease which resembles smallpox but with a lower person-to-person transmission rate. To determine the genetic relationship between the orthopoxviruses causing these two diseases, we sequenced the 197-kb genome of MPV isolated from a patient during a large human monkeypox outbreak in Zaire in 1996. The nucleotide sequence within the central region of the MPV genome, which encodes essential enzymes and structural proteins, was 96.3% identical with that of variola (smallpox) virus (VAR). In contrast, there were considerable differences between MPV and VAR in the regions encoding virulence and host-range factors near the ends of the genome. Our data indicate that MPV is not the direct ancestor of VAR and is unlikely to naturally acquire all properties of VAR

Luminescence of Ion-Pair States of Halogens in Liquid Perfluorocarbons

The I2(D′−A′) luminescence in liquid C7F16, C8F18, C9F20, and C12F26 has been observed following irradiation with visible (within the I2 X → B band region) and UV (λ < 300 nm) lasers. The band is shifted by ∼2000 cm−1 to the red relative to the gas phase and is significantly broader (fwhm ≈ 3000 cm−1 vs 500 cm−1 in the gas phase). Two-color excitation of other halogens in CnF2n+2 solvents revealed similarly shifted and strongly broadened D′−A′ bands of Br2, IBr, and BrCl. The stability of the ion-pair states of halogens in room temperature liquids opens new experimental opportunities for condensed phase studies and may be of applied interest considering the increasing industrial applications of perfluorocarbons

Economic models of fish shoal (school) size: a near comprehensive view of single species shoaling strategy

Flock, Herd, Optimum shoal size, Defense, Food patches, Collective good, Free-riding, Comparative static analysis, Marginal, D71,