| 1. |
- Endrődi, Balázs, 1987-, et al.
(författare)
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Challenges and rewards of the electrosynthesis of macroscopic aligned carbon nanotube array/conducting polymer hybrid assemblies
- 2015
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Ingår i: Journal of Polymer Science Part B. - : Wiley. - 0887-6266 .- 1099-0488. ; 53, s. 1507-1518
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Tidskriftsartikel (refereegranskat)abstract
- Hybrid assemblies based on conducting polymers and carbon nanomaterials with organized nanoscale structure are excellent candidates for various application schemes ranging from thermal management to electrochemical energy conversion and storage. In the case of macroscopic samples, however, precise control of the nanoscale structure has remained a major challenge to be solved for the scientific community. In this study we demonstrate possible routes to homogeneously infiltrate poly(3-hexylthiophene), poly(3,4-ethylenedioxythiophene), and polyaniline into macroscopic arrays of vertically aligned multiwalled carbon nanotubes (MWCNTAs). Electron microscopic images and Raman spectroscopic analysis (performed along the longitudinal dimension of the hybrid samples) both confirmed that optimization of the electropolymerization circumstances allowed fine tuning of the hybrid structure towards the targeted application. In this vein, three different application avenues were tested. The remarkable anisotropy in both the electrical and thermal conductivity of the nanocomposites makes them eminently attractive candidates to be deployed in thermal management. Thermoelectric studies, aimed to understand the effect of organized nanoscale morphology on the important parameters (Seebeck coefficient, electrical-, and thermal conductivity) compared to their non-organized hybrid counterparts. Finally, extraordinary high charge storage capacity values were registered for the MWCNTA/PANI hybrids (500 F g−1 and 1–3 F cm−2).
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| 2. |
- Balazs, Csaba, et al.
(författare)
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Interpreting the Fermi-LAT gamma ray excess in the simplified framework
- 2015
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Ingår i: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 92:12
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Tidskriftsartikel (refereegranskat)abstract
- We test the plausibility of the hypothesis that the annihilation of a Majorana fermion dark matter particle via a scalar mediator explains the gamma ray excess from the Galactic center. Assuming that the mediator couples to all third generation fermions we calculate observables for dark matter abundance and scattering on nuclei, gamma, positron, and antiproton cosmic ray fluxes, radio emission from dark matter annihilation, and the effect of dark matter annihilations on the CMB. After discarding the controversial radio observation, we show that the dark matter model simultaneously fits the observed excesses in the cosmic gamma ray, the positron, and antiproton fluxes, while evading constraints from the CMB and direct detection. The experimental data are consistent with a dark matter (mediator) mass in the 10-100 (3-1000) GeV region and with weakly correlated couplings to bottom quarks and tau leptons with values of 10(-3) - 1 at the 68% credibility level.
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