13,258 research outputs found
Aquaculture for the poor in Cambodia
This lesson learned reviewed the current status of aquaculture in Cambodia. It primarily covers inland fish farming development and coastal aquaculture projects targeted at poverty alleviation and food security. It focuses on approaches aimed at developing low cost systems, and less on high input aquaculture systems that are usually inaccessible to poor families.
Heavy pseudoscalar-meson decay constants with strangeness from the extended nonlocal chiral-quark model
We study the weak-decay constants for the heavy pseudoscalar mesons, D, Ds,
B, and Bs. For this purpose, we employ the extended nonlocal chiral-quark model
(ExNLChQM), motivated by the heavy-quark effective field theory as well as the
instanton-vacuum configuration. In addition to the heavy-quark symmetry and the
nonlocal interactions between quarks and pseudoscalar mesons in ExNLChQM, a
correction for the strange-quark content inside Ds and Bs is also taken into
account and found to be crucial to reproduce the empirical values. From those
numerical results, we obtain f_{D,Ds,B,Bs}=(207.53, 262.56, 208.13, 262.39)
MeV, which are in good agreement with experimental data and other theoretical
estimations. Using those numerical results, we compute the CKM matrix elements
and the Cabibbo angle, using various mesonic and leptonic heavy-meson decay
channels, resulting in
(|V_{cd}|,|V_{cs}|,|V_{ub}|,|V_{td}|/|V_{ts}|)=(0.224,0.968,<5.395*10^{-3},0.215)
and theta_C=12.36^o which are well compatible with available data.Comment: 12 pages, 7 figures, accepted for publication in Mod. Phys. Lett.
Inverted polymer fullerene solar cells exceeding 10% efficiency with poly(2-ethyl-2-oxazoline) nanodots on electron-collecting buffer layers
Polymer solar cells have been spotlighted due to their potential for low-cost manufacturing but their efficiency is still less than required for commercial application as lightweight/flexible modules. Forming a dipole layer at the electron-collecting interface has been suggested as one of the more attractive approaches for efficiency enhancement. However, only a few dipole layer material types have been reported so far, including only one non-ionic (charge neutral) polymer. Here we show that a further neutral polymer, namely poly(2-ethyl-2-oxazoline) (PEOz) can be successfully used as a dipole layer. Inclusion of a PEOz layer, in particular with a nanodot morphology, increases the effective work function at the electron-collecting interface within inverted solar cells and thermal annealing of PEOz layer leads to a state-of-the-art 10.74% efficiency for single-stack bulk heterojunction blend structures comprising poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-alt-3-fluorothieno[3,4-b]thiophene-2-carboxylate] as donor and [6,6]-phenyl-C71-butyric acid methyl ester as acceptor
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