Coherently moving flocks of birds, beasts or bacteria are examples living matter with spontaneous orientational order. How do these systems differ from thermal equilibrium such liquid-crystalline order? Working a fluidized monolayer macroscopic rods in the nematic liquid crystalline phase, we find giant number fluctuations consistent standard deviation growing linearly mean, contrast to any situation where Central Limit Theorem applies. These long-lived, decaying only as logarithmic function...

Energy harvesting from vibrations is demonstrated using a nanogenerator composed of piezoelectric polymer nanowires with high energy conversion efficiency. Nanowires poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) grown simple, scalable, and cost-effective template-wetting technique are shown to be successfully exploited in high-performance nanogenerators without the need for electrical poling. Nanogenerators based on materials convert ever-present mechanical into power...

Thermoelectric materials, capable of interconverting heat and electricity, are attractive for applications in thermal energy harvesting as a means to power wireless sensors, wearable devices, portable electronics. However, traditional inorganic thermoelectric materials pose significant challenges due high cost, toxicity, scarcity, brittleness, particularly when it comes requiring flexibility. Here, we investigate organic–inorganic nanocomposites that have been developed from bespoke inks...

We study experimentally the nonequilibrium phase behaviour of a horizontal monolayer macroscopic rods. The motion rods in two dimensions is driven by vibrations vertical direction. Aside from control variables packing fraction and aspect ratio that are typically explored molecular liquid crystalline systems, due to size particles we also able investigate effect precise shape particle on steady states this system. find plays an important role determining nature orientational ordering at high...

Aerosol-jet printing allows functional materials to be printed from inks with a wide range of viscosities and constituent particle sizes onto various substrates, including the organic thermoelectric on flexible substrates for low-grade thermal energy harvesting. However, these typically suffer relatively poor performance, compared traditional inorganic counterparts, due their low Seebeck coefficient, S, electrical conductivity, σ. Here, we demonstrate modified aerosol-jet technique that can...

Abstract Topological insulators (TIs) are bulk with exotic ‘topologically protected’ surface conducting modes. It has recently been pointed out that when stacked together, interactions between modes can induce diverse phases including the TI, Dirac semimetal, and Weyl semimetal. However, currently a full experimental understanding of conditions under which topological interact is lacking. Here, working multilayers TI Sb 2 Te 3 band insulator GeTe, we provide evidence multiple in single...

Abstract Thermoelectric generators (TEGs) operate in the presence of a temperature gradient, where constituent thermoelectric (TE) material converts heat into electricity via Seebeck effect. However, TE materials are characterized by figure merit ( ZT ) and/or power factor (PF), which often has strong dependence on temperature. Thus, single spanning given range is unlikely to have an optimal or PF across entire range, leading inefficient TEG performance. Compositionally graded...

A neural network model has been developed on the basis of published experimental data. This allows creep rupture strength bainitic and martensitic electric power plant steels with compositions based Fe–2·25Cr–1Mo Fe–(9–12)Cr to be estimated as a function chemical composition, heat treatment time at temperature. model, together variety thermodynamic kinetic calculations, used propose two new alloys related 10CrMoW steel which in theory have outstanding properties.

The hot torsion stress-strain curves of steels have been modelled using a neural network, within Bayesian framework. analysis is based on an extensive database consisting detailed chemical composition, temperature and strain rate from new experiments. Non-linear functions are obtained, describing the variation with composition. Predictions associated error bars, whose magnitude depends their position in input space. From population possible models, "committee models" found to give most...

Transition metal complexes of a number 1-substituted tetrazoline-5-thiones have been prepared and their infrared spectra examined in the 3 600 – 500 cm −1 region. The analytical applications for gravimetric determination cadmium palladium studied.

We propose and model an experiment where impurity profiles in low dimensional structures can be controlled (during heat treatment) by external parabolic potential defined a variety of gate arrangements. At high temperatures the impurities are ionized able to move relatively quickly. After realistic equilibrium time typically one hour, rapidly cooled such that frozen place. The model, which takes electronic distribution as well mobile into account results nonlinear Poisson equation. Similar...

We report the room-temperature growth of vertically aligned ternary Bi2-xSbxTe₃ nanowires diameter ~200 nm and length ~12 µm, within flexible track-etched nanoporous polycarbonate (PC) templates via a one-step electrodeposition process. with compositions spanning entire range from pure Bi₂Te₃ (x = 0) to Sb₂Te₃ 2) were systematically grown channels PC tartaric-nitric acid based electrolyte, at end which highly crystalline uniform composition obtained. Compositional analysis showed that Sb...

We investigate the electromechanical interactions in individual P(VDF-TrFE) nanowires response to localized electrical poling via a conducting atomic force microscope tip. Spatially resolved measurements of piezoelectric coefficients and elastic moduli before after reveal striking dependence on polarity field, notably absent thin films same composition. These observations are attributed unclamped nature inherent asymmetry their chemical with tip underlying substrate. Our findings provide...

The lattice constants of the γ and γ' phases nickel base superalloys have been modelled using a neural network within Bayesian framework. analysis is based on datasets compiled from new experiments published literature, parameters being expressed as non-linear function some eighteen variables which include chemical composition temperature. permits estimation error bars whose magnitude depends their position in input space. Of many models possible, "committee models" found to give most...

By combining $n$-type $\mathrm{Bi_2Te_3}$ and $p$-type $\mathrm{Sb_2Te_3}$ topological insulators, vertically stacked $p$-$n$ junctions can be formed, allowing to position the Fermi level into bulk band gap also tune between $n$- surface carriers. Here we use low-temperature magnetotransport measurements probe transport modes in a range of vertical $\mathrm{Bi_2Te_3/Sb_2Te_3}$ heterostructures with varying relative thicknesses top bottom layers. With increasing thickness layer observe change...

We present thermal and electrical transport measurements of low-density (10$^{14}$ m$^{-2}$), mesoscopic two-dimensional electron systems (2DESs) in GaAs/AlGaAs heterostructures at sub-Kelvin temperatures. find that even the supposedly strongly localised regime, where resistivity system is two orders magnitude greater than quantum resistance $h/e^2$, thermopower decreases linearly with temperature indicating metallicity. Remarkably, exceeds predicted value non-interacting metallic 2DESs...

We report the development of a simple and reliable, front-sided-only fabrication technique for n-type ohmic contacts to two-dimensional electron gases (2DEGs) in undoped GaAs/AlGaAs quantum wells. have adapted well-established recessed contacts/insulated metal gate inducing 2DEG an triangular well also work reliably square Our adaptation involves change procedure etching contact pits optimise etch side-wall profile depth. As application our technique, we present front-side-gated ambipolar...

We propose an experiment, where impurity diffusion in a semiconductor layer during heat treatment, can be controlled by nonlinear potential produced split gates. approximated the as parabola centered at middle of layer; impurities diffuse into central region. Starting with phenomenological Arrhenius equation, we describe simple model for diffusion, and then perform Monte Carlo simulations to predict profile, different parabolic constants densities. The results show that charge builds up area...

On the basis of experiments using monolayers spherical grains, Aranson et al. suggest that giant number fluctuations we observed in active granular rods may be explained by static inhomogeneity or inelastic clustering. We refute these alternative explanations and underline evidence originate nematic ordering.

Topological defects are ubiquitous from solid state physics to cosmology, where they drive phase transitions by proliferating as domain walls, monopoles or vortices. As quantum excitations, often display fractional charge and anyonic statistics, making them relevant topologically protected computation, but realizing a controlled physical resource for topological excitations has been difficult. Here we report evidence of during the localization transition in strongly interacting...

We present thermopower S and resistance R measurements on GaAsbased mesoscopic two-dimensional electron gases (2DEGs) as functions of the density n s .At high we observe good agreement between measured MOTT , Mott prediction for a non-interacting metal.As is lowered, crossover from Mott-like behaviour to that where shows strong oscillations even sign changes.Remarkably, there are absolutely no features in corresponding those S. In fact, devoid any universal conductance fluctuations.A...

We propose and model several experiments where the field effect defined by split gates is used to restrict acceptors donors regions of a semiconductor layer. The nonlinear potential restricts positive center layer, whereas negative localize near edges. Arrhenius equation modified include effects external internal fields calculate time- position-dependent impurity hopping probabilities for Monte Carlo simulations experiments. results show that at high doping levels, resists concentrations net...

G. W. C. Milner, Tylor, S. M. Peach, A. R. V. Murthy, Narayan, Rao, J. F. Tyler, E. Weston and K. Hayden, Analyst, 1956, 81, 367 DOI: 10.1039/AN9568100367