5,054 research outputs found

    Interaction of metal phthalocyanines with carbon zigzag and armchair nanotubes with different diameters

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    Quantum-chemical calculations of the association of metal free, cobalt, copper and zinc phthalocyanines (MPc) with carbon zigzag and armchair nanotubes (CNTs) with diameters in the range of 7–14 Å were carried out by the DFT method with the use of BH van der Waals density functional and DZP atomic basis set. It was shown that interaction energy between the phthalocyanine molecules and the CNTs, as a whole, increases with an increase of the diameter of carbon nanotubes. However, in the case of CNT(n,0) the energy reaches its maximal value at n = 16 or 17 depending on the central metal atom and phthalocyanine orientation on the carbon nanotubes surface. Up to diameter of 10.5 Å of the CNTs, stronger binding of the considered MPc macrocyclic molecules is observed with carbon armchair nanotubes. However, in the case of higher diameters the phthalocyanines are associated more strongly with the zigzag CNTs

    Numerical Computations with H(div)-Finite Elements for the Brinkman Problem

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    The H(div)-conforming approach for the Brinkman equation is studied numerically, verifying the theoretical a priori and a posteriori analysis in previous work of the authors. Furthermore, the results are extended to cover a non-constant permeability. A hybridization technique for the problem is presented, complete with a convergence analysis and numerical verification. Finally, the numerical convergence studies are complemented with numerical examples of applications to domain decomposition and adaptive mesh refinement.Comment: Minor clarifications, added references. Reordering of some figures. To appear in Computational Geosciences, final article available at http://www.springerlink.co

    COAUTHOR - a MoU to create a COnsortium of Academics from Universities promoting the use of THORium

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    This paper describes the Memorandum of Understanding (MoU) signed by the authors to create a future consortium of academics from universities to promote the utilization of thorium (COAUTHOR). Besides the description of the MoU, also results of the research conducted in each participating partner or collaborative work performed among them will be described. Finally, the future work planned in the framework of the MoU, will be discussed

    A MoU to create a COnsortium of Academics from Universities promoting the use of THORrium (COAUTHOR)

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    Nuclear Energy, primarily to produce electricity and other use, and the enveloping Nuclear Technology, as inherited from the XX Century, constitutes a controversial issue for political and economic reasons. On the one hand, the energy source is promoted in several Countries and an unavoidable mean to ensure growth for the human civilization ad suitable living standard with reduced or no impact upon the environment, on the other hand it is abandoned or going to be abandoned in other Countries which did benefit of stable economic growth. Thorium is an emblem for such a situation: huge reserves are available all over the world (primarily India, Turkey, and Brazil, but not only) and its technological worth for exploitation in current generation of thermal fission reactors is demonstrated, on the other hand no industrial use is ongoing or planned for the near future (with an exception constituted by situation in India). Moreover, research on thorium utilization in nuclear reactors and associated fuel cycles has been of academic interest for many researchers around the world. These researches are being conducted to increase the natural resource utilization, reduces the radiotoxicity, and other criteria of sustainability, by using thorium in the present time advanced reactors (Generation III), as well for the future Generation IV, mainly in Molten Salt Reactors (MSR) and in hybrid fusion/ accelerators driven system. Here we are going to describe a MoU signed by the authors to promote the utilization of thorium as nuclear fuel, and shortly describe the research activities conducted by the MoU partners

    The state of the art in non-pharmacological interventions for developmental stuttering. Part 1: a systematic review of effectiveness

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    Background The growing range of available treatment options for people who stutter presents a challenge for clinicians, service managers and commissioners, who need to have access to the best available treatment evidence to guide them in providing the most appropriate interventions. While a number of reviews of interventions for specific populations or a specific type of intervention have been carried out, a broad-based systematic review across all forms of intervention for adults and children was needed to provide evidence to underpin future guidelines, inform the implementation of effective treatments and identify future research priorities. Aims To identify and synthesize the published research evidence on the clinical effectiveness of the broad range of non-pharmacological interventions for the management of developmental stuttering. Methods & Procedures A systematic review of the literature reporting interventions for developmental stuttering was carried out between August 2013 and April 2014. Searches were not limited by language or location, but were restricted by date to studies published from 1990 onwards. Methods for the identification of relevant studies included electronic database searching, reference list checking, citation searching and hand searching of key journals. Appraisal of study quality was performed using a tool based on established criteria for considering risk of bias. Due to heterogeneity in intervention content and outcomes, a narrative synthesis was completed. Main Contribution The review included all available types of intervention and found that most may be of benefit to at least some people who stutter. There was evidence, however, of considerable individual variation in response to these interventions. The review indicated that effects could be maintained following all types of interventions (although this was weakest with regard to feedback and technology interventions). Conclusions This review highlights a need for greater consensus with regard to the key outcomes used to evaluate stuttering interventions, and also a need for enhanced understanding of the process whereby interventions effect change. Further analysis of the variation in effectiveness for different individuals or groups is needed in order to identify who may benefit most from which intervention

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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