75 research outputs found
Author Correction: The messy death of a multiple star system and the resulting planetary nebula as observed by JWST
Stars and planetary system
Effect of Nanosilica Additions on Belite Cement Pastes Held in Sulfate Solutions
4 pages.-- Final full-text version of the paper available at: http://dx.doi.org/10.1111/j.1551-2916.2007.02034.x.Fly Ash Belite Cement (FABC) pastes with and without nanosilica additions have been prepared and maintained in sulfate solutions (Na2SO4 0.5M) for 180 days. The mechanical performance and the changes in microstructure have been monitored at 28, 90, and 180 days by compressive strength, X-ray diffraction (XRD), and 29Si MAS NMR measurements. We have found that, unexpectedly, and contrary to what happens in Ordinary Portland Cements (OPC), the addition of nanosilica particles induces an initial decline in the compressive strength of the samples. Only in samples maintained for a long time (180 days) does the nanosilica addition improve the mechanical properties. Our XRD and 29Si NMR experiments have revealed that although nanosilica additions trigger the consumption of Belite phases, this is not always accompanied by formation of longer calciumâsilicateâhydrate (CâSâH) gel structures. Only at a long time (180 days), and due to a mechanism that seems to
be controlled by the pH of the samples, do the nanosilica additions lead to high-polymerized CâSâH gels.This work was financially supported by the Spanish Government (Projects no. MAT 2002-04023-CO1-CO2-CO3 and MAT2005-03890).Peer reviewe
The putative nebula of the Wolf-Rayet WR 60 star: a case of mistaken identity and reclassification as a new supernova remnant G310.5+0.8
Isolated microspore culture overperforms anther culture for green plant regeneration in barley (Hordeum vulgare L.)
Measurement of the absolute branching fraction for Îc+âÎÎź+νΟ
We report the first measurement of the absolute branching fraction for Îc+âÎÎź+νΟ. This measurement is based on a sample of e+eâ annihilation data produced at a center-of-mass energy s=4.6 GeV, collected with the BESIII detector at the BEPCII storage rings. The sample corresponds to an integrated luminosity of 567 pbâ1. The branching fraction is determined to be B(Îc+âÎÎź+νΟ)=(3.49Âą0.46(stat)Âą0.27(syst))%. In addition, we calculate the ratio B(Îc+âÎÎź+νΟ)/B(Îc+âÎe+νe) to be 0.96Âą0.16(stat)Âą0.04(syst)
Possible realization of entanglement, logical gates, and quantum-information transfer with superconducting-quantum-interference-device qubits in cavity QED
Evolution of LPSO Phases and Their Effect on Dynamic Recrystallization in a Mg-Gd-Y-Zn-Zr Alloy
The messy death of a multiple star system and the resulting planetary nebula as observed by JWST
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