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n-type Bi2(Te0.90Se0.10)3/(SiC)y (0 ≤ y ≤ 0.01) composites with nano-SiC were fabricated by mechanical alloying combined with microwave sintering. The microstructure and thermoelectric properties of Bi2(Te0.90Se0.10)3/(SiC)y were studied systematically. The nano-SiC particles as the phonon scattering center uniformly distributed in the matrix, with little effect on the electric transport performance and significantly reducing the thermal conductivity of n-type Bi2(Te0.90Se0.10)3/(SiC)y (0 ≤ y ≤ 0.01). The introduction of nano-SiC optimizes the thermoelectric performance, and the sample with SiC y = 0.0075 obtains the highest ZT~0.94 at 323 K.

Noise and greenhouse gas emission targets set by e.g., the EU commission, NASA, and ICAO oblige the aviation industry to reduce its environmental footprint. Battery-powered hybrid-electric aircraft are currently being investigated in this regard as they can potentially reduce in-flight greenhouse gas emissions and noise. However, most studies to date have focused on the CO2 emission reduction potential instead of considering the total life cycle environmental impact. Hence, within this study an environmental life cycle assessment method for a hybrid-electric aircraft is developed and applied, supplemented by a direct operating costs analysis. This allows the simultaneous evaluation of the environmental impact reduction potential and the economic consequences for aircraft operators. This demonstrates the faced trade-off and contributes to a meaningful review process. A single-aisle transport aircraft (A320 class) serves as a use case for the established methodology. It consists of the conceptual aircraft design, the environmental life cycle assessment, and the direct operating costs analysis for a conventional reference aircraft and a hybrid-electric aircraft with a discrete parallel powertrain architecture. It should be noticed that the focus of this study is the comparison of conceptual aircraft designs of the same fidelity on system level, in lieu of the detailed modeling of a hybrid-electric aircraft. Results show that for a degree of hybridization of 0.3, the environmental impact of the hybrid-electric configuration increased by $$15.1\%$$ 15.1 % , while the operating costs increased by $$41.0\%$$ 41.0 % compared to a conventional reference aircraft. For a future scenario, favourable for hybrid-electric aircraft with i.a. renewable electricity production, the environmental impact could be reduced by $$7.0\%$$ 7.0 % compared to the reference aircraft. At the same time, the operating costs gap between both configurations decreases to $$+ 26.8\%$$ + 26.8 % . Hybrid-electric aircraft should therefore be investigated further as a potential solution to reduce the environmental impact of aviation, if simultaneously to developing them the expansion of renewable energies is fostered. Nevertheless, this reduction in environmental impact involves a high direct operating costs penalty.

Graphene, a two-dimensional structure of carbon, due to its structure has unique physico-chemical properties that can be used in numerous research and industry areas. Although this structure is already well known, there are still technological (and cost) barriers which do not allow to produce this material in large quantities and hence prevent its use in various applications. For this reason, many technologies are currently being developed to obtain graphene in forms that would enable its widespread use. The graphene-like ceramics were fabricated by the high isostatic pressure method at different temperatures. This technique allows to obtain dense ceramics with various shapes. The structure and morphology of sintered graphene were investigated by XRD, SEM and the Raman spectroscopy. The hardness, thermal conductivity and electric transport measurements recorded in a wide range of temperatures were used to analyze the physical properties of the obtained ceramics.

The review discusses the problems of development of sodium-ion batteries intended to replace lithium-ion batteries used in large power plants (electric transport, smart grids). The literature data, mainly for the last five years, devoted to electrode functional materials and electrolytes used in sodium-ion batteries are presented and analyzed.

We develop a nonlinear theory of the electronic transport in superconductors in the framework of the time-dependent Ginzburg-Landau (TDGL) equation. We utilize self-consistent Gaussian approximation and reveal the conditions under which the current-voltage V(I) dependence (I–V characteristics) acquires an S-shape form leading to switching instabilities. We demonstrate that in two-dimensions the emergence of such an instability is a hallmark of the Berezinskii-Kosterlitz-Thouless (BKT) transition that we have detected by transport measurements of titanium nitride (TiN) films. Our theoretical findings compare favorably with our experimental results.

Electrical resistivity of La2NiO4+ δ single crystals has been investigated. Results showed several anomalies that are related to the onset of spin and charge ordering, either static or dynamic.

The structural and magnetic properties in two perovskite manganites with the small Y, Ca cations were investigated using neutron diffraction combined with magnetic and electric transport measurements. The system Y0.7Ca0.3MnO3 displays a cooperative Jahn–Teller ordering of the LaMnO3 kind. Manganese spins are largely frustrated with some short-range correlations of the antiferromagnetic or canted type, while relatively large net magnetization can be induced by an external field. The compound Y0.5Ca0.5MnO3 exhibits a Mn3+/Mn4+ (1:1) charge ordering below 290 K, followed at 115 K with a CE-type antiferromagnetic transition.

Electric transport and magnetoresistance characteristics were investigated for Fe3O4-x Fe(x=0, 10, 20 wt.%) samples and Fe3O4-α-Fe2O3 samples sintered at 500°C. For composition dependence of Fe3O4-x Fe samples, the largest room temperature MR, 3.3% at 10 kOe, was obtained from a Fe3O4-10 Fe sample. For the surface heat treatment dependence of Fe3O4 powders, the largest room temperature MR, 4% at 10 kOe, was obtained from a Fe3O4-α-Fe2O3 sample sintered with Fe3O4 powders heated at 200°C in air. It was found that these enhanced MR ratios always appear together with the appropriate excess resistance which is regarded as the tunneling barrier. These enhanced MR ratios of Fe3O4-10 Fe and Fe3O4-α-Fe2O3 samples can be explained by the increased interparticle contact sites and the appropriate thickness of α-Fe2O3, respectively.

Three new phases with compositions, LaSr2FeTiO7, NdSr2FeTiO7 and GdSr2FeTiO7, were prepared by the traditional ceramic method. Lazy-Pulverix analysis of the X-ray diffraction data suggests that the phases crys- tallize in the RP-type (n = 2) structure in the space group, I4/mmm. The cell dimensions along the c-axis decrease with decrease in size of the rare earth ions. Electrical resistivity, as a function of temperature, shows that the mate- rials are insulators and the resistivity decreases with decrease in the size of the rare earth ion, which is attributed to increase in the three-dimensional character.

We study resistor diode percolation at the transition from the non-percolating to the directed percolating phase. We derive a field theoretic Hamiltonian which describes not only geometric aspects of directed percolation clusters but also their electric transport properties. By employing renormalization group methods we determine the average two-port resistance of critical clusters, which is governed by a resistance exponent φ. We calculate φ to two-loop order.

Sr3Ru2O7 and Sr3Ru1.5Fe0.5O7 have been prepared by the ceramic method. XRD studies show that the phases crystallize as tetragonal unit cells with the space groupI4/mmm. Electric conduction in these phases follows variable range-hopping mechanism but the characteristic energy of hopping in Sr3Ru2O7 is reduced to a great extent. Magnetic susceptibility of Sr3Ru2O7 shows an abrupt rise below 200 K. Sr3Ru1.5Fe0.5O7 is antiferromagnetic.

A remarkable nonlinearity has been observed for electric transport in K-TCNQ (potassium tetracyanoquinodimethane) quasi-one-dimensional conductor. The negative differential resistance region appears afterV m (turn over voltage), beyond which voltage goes down with increase of current. A possible mechanism is discussed in terms of dynamics of charged solitons and domain walls in one-dimensional molecular stacks of these types of crystals.

Electric transport properties of sputtered YBa2Cu3O7−δ films were studied as a function of screw dislocation density, ranging from 5·107 cm−2 to 1.3·109 cm−2 as determined at the film surface. A correlation was found between the number of screw dislocations and the critical current density (J c ). Films with higher screw dislocation densities have higher critical current densities and a slower drop ofJ c as a function of applied magnetic fieldH.

The quantitative description of the motion of neurotransmitters in the synaptic cleft appears to be one of the most difficult problems in the modeling of synapses. Here we show in contradiction to the common view, that this process is merely governed by electric transport than diffusion forces.

In the wake of the Volkswagen emissions-testing scandal (see Nature http://doi.org/723; 2015), this month's climate summit in Paris needs to roll out an international framework for regulating emissions — with strong incentives and tough penalties. Voluntary national measures are no longer enough. Volkswagen's gaming of emissions testing underscores the urgency of reinventing transport. Governments must implement electric transport systems and plan for combustion-free inner cities, by expanding such schemes as London's ultralow-emission zone, due in 2020. Chancellor Angela Merkel could fast-track zero-emission zones for Berlin, Hamburg, Munich and Frankfurt by 2025, for example — restoring Germany's environmental lead. The Volkswagen debacle should be treated as an Enron moment for sustainability measurement and valuation, with a comparable overhaul of the requirements for corporate accounting and evaluation. Programmes such as the Redefining Value initiative of the World Business Council for Sustainable Development can capture environmental externalities, including impacts on climate, biodiversity and health. Now we just need governments to incorporate these into their regulatory and stock-market requirements.

A renormalization group study of electric transport in nanocontacts reveals the importance of quantum correlations for achieving a startling ferromagnetic Kondo effect.

An electric-transport method is described for introducing impurities into semiconducting oxides. Local inhomogeneities may be produced in the samples in this process. Certain physical properties of the samples may be changed by electric transport.