Emerg Infect Dis

The identification of new materials capable of sustaining a high electron emission current is a key requirement in the development of the next generation of cold cathode devices and technology. Compatibility with large volume material production methods is a further important practical consideration with solution chemistry-based methods providing for route to industrial scale-up. Here we demonstrate a new class of organic-inorganic hybrid material based on polypyrrole and zinc oxide (PPy/ZnO) nanofibers for use as a low-cost large-area cathode material. Solution chemistry based surfactant chemical oxidation polymerisation is used to synthesise the nanofibers and the macroscopic turn-on electric field for emission has been measured to be as low as 1.8 V/μm, with an emission current density of 1 mA/cm2 possible for an applied electric field of less than 4 V/μm. Specfic surface area measurements reveal a linear increase in the nanofiber surface area with ZnO incorporation, which when coupled with electron microscopy and x-ray diffraction analysis reveals that the wurtzite ZnO nanoparticles (around 45 nm in size) act as nucleation sites for the growth of PPy nanofibers. Our study demonstrates for the first time how an inorganic nanocrystal acting as a nucleation site allows for the tailored growth of the organic component without diminishing the overall electrical properties and opens the potential of a new type of organic-inorganic hybrid large-area cathode material. The broader impacts and advantages of using hybrid materials, when compared to other composite nanomaterial systems, as large area cathode materials are also discusse

Nano-Architecture of nitrogen-doped graphene films synthesized from a solid CN source

New synthesis routes to tailor graphene properties by controlling the concentration and chemical configuration of dopants show great promise. Herein we report the direct reproducible synthesis of 2-3% nitrogen-doped ‘few-layer’ graphene from a solid state nitrogen carbide a-C:N source synthesized by femtosecond pulsed laser ablation. Analytical investigations, including synchrotron facilities, made it possible to identify the configuration and chemistry of the nitrogen-doped graphene films. Auger mapping successfully quantified the 2D distribution of the number of graphene layers over the surface, and hence offers a new original way to probe the architecture of graphene sheets. The films mainly consist in a Bernal ABA stacking three-layer architecture, with a layer number distribution ranging from 2 to 6. Nitrogen doping affects the charge carrier distribution but has no significant effects on the number of lattice defects or disorders, compared to undoped graphene synthetized in similar conditions. Pyridinic, quaternary and pyrrolic nitrogen are the dominant chemical configurations, pyridinic N being preponderant at the scale of the film architecture. This work opens highly promising perspectives for the development of self-organized nitrogen-doped graphene materials, as synthetized from solid carbon nitride, with various functionalities, and for the characterization of 2D materials using a significant new methodology

The development of a stakeholder-based scale for measuring corporate social responsibility in the banking industry.

ABSTRACT: Research on corporate social responsibility (CSR) has notably increased in recent years and many scales for measuring CSR image have been developed in academic literature. Due to the contextual character recognized in the implementation of CSR strategies, in this paper a new scale based on stakeholder theory is developed to evaluate customers’ perception regarding the CSR performance of their banking service providers. The proposal of reliable measurement tools for evaluating customers’ perception is especially relevant for companies because of their significant role in influencing the design and implementation of corporate strategies. Results demonstrate the reliability and validity of this new scale in two different samples. In the banking industry, CSR includes corporate responsibilities toward customers, shareholders, employees, society, and all legal and ethical requirements of banking institutions. Nevertheless, different kinds of banking institutions have specific CSR images, which reveal different strategic approaches to CSR

Accuracy versus precision in boosted top tagging with the ATLAS detector

Abstract The identification of top quark decays where the top quark has a large momentum transverse to the beam axis, known as top tagging, is a crucial component in many measurements of Standard Model processes and searches for beyond the Standard Model physics at the Large Hadron Collider. Machine learning techniques have improved the performance of top tagging algorithms, but the size of the systematic uncertainties for all proposed algorithms has not been systematically studied. This paper presents the performance of several machine learning based top tagging algorithms on a dataset constructed from simulated proton-proton collision events measured with the ATLAS detector at √ s = 13 TeV. The systematic uncertainties associated with these algorithms are estimated through an approximate procedure that is not meant to be used in a physics analysis, but is appropriate for the level of precision required for this study. The most performant algorithms are found to have the largest uncertainties, motivating the development of methods to reduce these uncertainties without compromising performance. To enable such efforts in the wider scientific community, the datasets used in this paper are made publicly available.</jats:p

Combination of searches for resonant Higgs Boson pair production using pp collisions at √s = 13 TeV with the ATLAS detector

A combination of searches for a new resonance decaying into a Higgs boson pair is presented, using up to 139  fb−1 of pp collision data at √s = 13 TeV recorded with the ATLAS detector at the LHC. The combination includes searches performed in three decay channels: b ¯ b ⁢b ¯ b , b⁢ ¯ b ⁢τ+⁢τ−, and b⁢ ¯ bγγ ⁢. No excess above the expected Standard Model background is observed and upper limits are set at the 95% confidence level on the production cross section of Higgs boson pairs originating from the decay of a narrow scalar resonance with mass in the range 251 GeV–5 TeV. The observed (expected) limits are in the range 0.96–600 fb (1.2–390 fb). The limits are interpreted in the type-I two-Higgs-doublet model and the minimal supersymmetric standard model, and constrain parameter space not previously excluded by other searches

Organic-inorganic hybrid cathodes: Facile synthesis of polypyrrole/zinc oxide nanofibers for low turn-on electron field emitters

The identification of new materials capable of sustaining a high electron emission current is a key requirement in the development of the next generation of cold cathode devices and technology. Compatibility with large volume material production methods is a further important practical consideration with solution chemistry-based methods providing for route to industrial scale-up. Here we demonstrate a new class of organic-inorganic hybrid material based on polypyrrole and zinc oxide (PPy/ZnO) nanofibers for use as a low-cost large-area cathode material. Solution chemistry based surfactant chemical oxidation polymerisation is used to synthesise the nanofibers and the macroscopic turn-on electric field for emission has been measured to be as low as 1.8 V/μm, with an emission current density of 1 mA/cm2 possible for an applied electric field of less than 4 V/μm. Specfic surface area measurements reveal a linear increase in the nanofiber surface area with ZnO incorporation, which when coupled with electron microscopy and x-ray diffraction analysis reveals that the wurtzite ZnO nanoparticles (around 45 nm in size) act as nucleation sites for the growth of PPy nanofibers. Our study demonstrates for the first time how an inorganic nanocrystal acting as a nucleation site allows for the tailored growth of the organic component without diminishing the overall electrical properties and opens the potential of a new type of organic-inorganic hybrid large-area cathode material. The broader impacts and advantages of using hybrid materials, when compared to other composite nanomaterial systems, as large area cathode materials are also discusse