Electrodes for sealed secondary batteries

Self-supporting membrane electrode structures, in which active ingredients and graphite are incorporated in a polymeric matrix, improve performance of electrodes in miniature, sealed, alkaline storage batteries

Possible phases of two coupled n-component fermionic chains

A two-leg ladder with $n$-component fermionic fields in the chains has been considered using an analytic renormalization group method. The fixed points and possible phases have been determined for generic filling as well as for a half-filled system and for the case when one of the subbands is half filled. A weak-coupling Luttinger-liquid phase and several strong-coupling gapped phases have been found. In the Luttinger liquid phase, for the most general spin dependence of the couplings, all $2n$ modes have different velocities if the interband scattering processes are scaled out, while $n$ doubly degenerate modes appear if the interband scattering processes remain finite. The role of backward-scattering, charge-transfer and umklapp processes has been analysed using their bosonic form and the possible phases are characterized by the number of gapless modes. As a special case the SU($n$) symmetric Hubbard ladder has been investigated numerically. It was found that this model does not scale to the Luttinger liquid fixed point. Even for generic filling gaps open up in the spectrum of the spin or charge modes, and the system is always insulator in the presence of umklapp processes

Instrument for measuring potentials on two dimensional electric field plots Patent

Instrument for measuring potentials on two dimensional electric field plo

Modelling and evaluation of a biomethane truck for transport performance and cost

This article compares a conventional diesel-fuelled heavy goods vehicle with one that runs on compressed gas (CG): either Compressed Natural Gas (CNG) or biomethane. It includes an evaluation of the transport performance, carbon emissions, and total costs. 41 CG trucks were trialled by a supermarket, delivering goods from their distribution centre. One of the vehicles was instrumented with a gas flow meter, which measured the gas consumption, and a smartphone based data logger, which collected data from the truck's Fleet Management System (FMS) interface. Similarly, a baseline diesel truck was instrumented. Based on the measurements that were collected in-service, fuel consumption models were developed and validated. Using the validated models, the CG and diesel trucks were compared for their transport performance, costs and carbon emissions. In addition, the vehicles were evaluated using telematics data and refuelling data from a year of transport operations for all 41 CG trucks and 9 diesel trucks. The results show that for a tonne.km of in-service (mostly long haul) transport work, compared to the diesel trucks, the CG trucks spend on average 22% more energy and their fuel cost is 30% lower for biomethane. When running on CNG, their equivalent carbon emissions is 10% lower than the baseline diesel, and when running on biomethane, their equivalent carbon emissions is 78% lower. Compared to long haul, the benefits are lower for regional operations, and are the lowest for city centre operations where using CNG, the CG truck's equivalent carbon emissions is higher than the diesel truck

The National Airline Passenger Survey 2014

The Airline Passenger Survey is conducted annually and participated in by frequent fliers who wish to contribute their experiences as an opinion-based alternative to the Airline Quality Rating. Passengers have responded to the request of researchers who wish to provide a consumer perspective on the quality of today\u27s air travel experience. Upon the collection and interpretation of results of the Airline Passenger Survey, they contribute a validation component to the quantitative data produced by the Airline Quality Rating

Interchain coherence of coupled Luttinger liquids at all orders in perturbation theory

We analyze the problem of Luttinger liquids coupled via a single-particle hopping \tp and introduce a systematic diagrammatic expansion in powers of \tp. An analysis of the scaling of the diagrams at each order allows us to determine the power-law behavior versus \tp of the interchain hopping and of the Fermi surface warp. In particular, for strong interactions, we find that the exponents are dominated by higher-order diagrams producing an enhanced coherence and a failure of linear-response theory. Our results are valid at any finite order in \tp for the self-energy.Comment: 4 pages, 3 ps figures. Accepted for publication in Phys. Rev. Let

Hall Effect in a Quasi-One-Dimensional System

We consider the Hall effect in a system of weakly coupled one-dimensional chains with Luttinger interaction within each chain. We construct a perturbation theory in the inter-chain hopping term and find that there is a power law dependence of the Hall conductivity on the magnetic field with an exponent depending on the interaction constant. We show that this perturbation theory becomes valid if the magnetic field is sufficiently large.Comment: 20 page

Spin Gap and Superconductivity in Weakly Coupled Ladders: Interladder One-particle vs. Two-particle Crossover

Effects of the interladder one-particle hopping, $t_{\perp}$, on the low-energy asymptotics of a weakly coupled Hubbard ladder system have been studied, based on the perturbative renormalization-group approach. We found that for finite intraladder Hubbard repulsion, $U$, there exists a crossover value of the interladder one-particle hopping, $t_{\perp c}$. For $0<t_{\perp}<t_{\perp c}$, the spin gap metal (SGM) phase of the isolated ladder transits at a finite transition temperature, $T_{c}$, to the d-wave superconducting (SCd) phase via a two-particle crossover. In the temperature region, $T<T_{c}$, interladder coherent Josephson tunneling of the Cooper pairs occurs, while the interladder coherent one-particle process is strongly suppressed. For $t_{\perp c}<t_{\perp}$, around a crossover temperature, $T_{cross}$, the system crosses over to the two-dimensional (2D) phase via a one-particle crossover. In the temperature region, $T<T_{cross}$, the interladdercoherent band motion occurs.Comment: 4 pages, 5 eps figures, uses jpsj.st

Crossover from Luttinger- to Fermi-liquid behavior in strongly anisotropic systems in large dimensions

We consider the low-energy region of an array of Luttinger liquids coupled by a weak interchain hopping. The leading logarithmic divergences can be re-summed to all orders within a self-consistent perturbative expansion in the hopping, in the large-dimension limit. The anomalous exponent scales to zero below the one-particle crossover temperature. As a consequence, coherent quasiparticles with finite weight appear along the whole Fermi surface. Extending the expansion self-consistently to all orders turns out to be crucial in order to restore the correct Fermi-liquid behavior.Comment: Shortened version to appear in Physical Review Letter

Dimensional crossover and metal-insulator transition in quasi-two-dimensional disordered conductors

We study the metal-insulator transition (MIT) in weakly coupled disordered planes on the basis of a Non-Linear Sigma Model (NL$\sigma$M). Using two different methods, a renormalization group (RG) approach and an auxiliary field method, we calculate the crossover length between a 2D regime at small length scales and a 3D regime at larger length scales. The 3D regime is described by an anisotropic 3D NL$\sigma$M with renormalized coupling constants. We obtain the critical value of the single particle interplane hopping which separates the metallic and insulating phases. We also show that a strong parallel magnetic field favors the localized phase and derive the phase diagram.Comment: 16 pages (RevTex), 4 poscript figure