1,448 research outputs found
Shock wave study and theoretical modeling of the thermal decomposition of c-C4F8
The thermal dissociation of octafluorocyclobutane, c-C4F8, was studied in shock waves over the range 1150-2300 K by recording UV absorption signals of CF2. It was found that the primary reaction nearly exclusively produces 2 C2F4 which afterwards decomposes to 4 CF2. A primary reaction leading to CF2 + C3F6 is not detected (an upper limit to the yield of the latter channel was found to be about 10 percent). The temperature range of earlier single pulse shock wave experiments was extended. The reaction was shown to be close to its high pressure limit. Combining high and low temperature results leads to a rate constant for the primary dissociation of k1 = 1015.97 exp(-310.5 kJ mol-1/RT) s-1 in the range 630-1330 K, over which k1 varies over nearly 14 orders of magnitude. Calculations of the energetics of the reaction pathway and the rate constants support the conclusions from the experiments. Also they shed light on the role of the 1,4-biradical CF2CF2CF2CF2 as an intermediate of the reaction.Fil: Cobos, Carlos Jorge. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Instituto de Investigaciones FisicoquÃmicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones FisicoquÃmicas Teóricas y Aplicadas; ArgentinaFil: Hintzer, K.. Dyneon Gmbh; AlemaniaFil: Sölter, L.. Universität Göttingen; AlemaniaFil: Tellbach, E.. Universität Göttingen; AlemaniaFil: Thaler, A.. Dyneon Gmbh; AlemaniaFil: Troe, J.. Universität Göttingen; Alemania. Max-Planck-Institut fu¨r biophysikalische Chemie; Alemani
-nucleus bound states
-nucleus bound state energies are calculated for various nuclei.
Essential input for the calculations, namely the medium-modified and
meson masses, as well as the density distributions in nuclei, are
calculated within the quark-meson coupling (QMC) model. The attractive
potentials for the meson in the nuclear medium originate from the
in-medium enhanced loops in the self-energy. Our results
suggest that the meson should form bound states with all the nuclei
considered.Comment: 8 pages, 6 figure
and Mesons in Cold Nuclear Matter
We present - and --nuclear bound state energies and absorption
widths for some selected nuclei, using potentials in the local density
approximation computed from an effective Lagrangian approach combined with the
quark-meson coupling model. Our results suggest that these mesons should form
bound states with all the nuclei considered provided that these mesons are
produced in nearly recoilless kinematics.Comment: Contribution to the Proceedings of 8th International Conference on
Quarks and Nuclear Physics (QNP2018), November 13-17, 2018, Tsukuba, Japan.
arXiv admin note: text overlap with arXiv:1711.0989
M2LADS: A System for Generating MultiModal Learning Analytics Dashboards
In this article, we present a Web-based System called M2LADS, which supports the integration and visualization of multimodal data recorded in learning sessions in a MOOC in the form of Web-based Dashboards. Based on the edBB platform, the multimodal data gathered contains biometric and behavioral signals including electroencephalogram data to measure learners' cognitive attention, heart rate for affective measures, visual attention from the video recordings. Additionally, learners' static background data and their learning performance measures are tracked using LOGCE and MOOC tracking logs respectively, and both are included in the Web-based System. M2LADS provides opportunities to capture learners' holistic experience during their interactions with the MOOC, which can in turn be used to improve their learning outcomes through feedback visualizations and interventions, as well as to enhance learning analytics models and improve the open content of the MOOC
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