589 research outputs found
On the Energetics of the HCO + C CH + CO Reaction and Some Astrochemical Implications
We explore the energetics of the titular reaction, which current
astrochemical databases consider open at typical dense molecular (i.e., dark)
cloud conditions. As is common for reactions involving the transfer of light
particles, we assume that there are no intersystem crossings of the potential
energy surfaces involved. In the absence of any such crossings, we find that
this reaction is endoergic and will be suppressed at dark cloud temperatures.
Updating accordingly a generic astrochemical model for dark clouds changes the
predicted gas-phase abundances of 224 species by greater than a factor of 2. Of
these species, 43 have been observed in the interstellar medium. Our findings
demonstrate the astrochemical importance of determining the role of intersystem
crossings, if any, in the titular reaction.Comment: Accepted for publication in ApJ; 14 pages, 2 figures, and 1 tabl
Nouveaux cas de tuberculose d’animaux sauvages
Urbain Achille, Nouvel Jacques, Rinjard Jean, Piette G. Nouveaux cas de tuberculose d’animaux sauvages. In: Bulletin de l'Académie Vétérinaire de France tome 104 n°6, 1951. pp. 321-323
Hemihepatectomy and Replacement of The Afferent Hepatic Blood Supply in The Dog
Hemihepatectomy along with portal vein or hepatic artery replacement in dogs was well tolerated, but
combined with replacement of both vessels it was lethal because of outflow block and shock. Total liver
blood flow should be kept as high as possible during such procedures in man
ERiSA: building emotionally realistic social game-agents companions
We propose an integrated framework for social and emotional game-agents to enhance their believability and quality of interaction, in particular by allowing an agent to forge social relations and make appropriate use of social signals. The framework is modular including sensing, interpretation, behaviour generation, and game components. We propose a generic formulation of action selection rules based on observed social and emotional signals, the agent’s personality, and the social relation between agent and player. The rules are formulated such that its variables can easily be obtained from real data. We illustrate and evaluate our framework using a simple social game called The Smile Game
Removal of imidacloprid using activated carbon produced from ricinodendron heudelotii shells
In this study, Ricinodendron heudelotii (akpi) shells are used as precursor to prepare activated carbon via chemical activation using phosphoric acid. The characterization of the obtained activated carbon is performed using X-ray diffraction (XRD), Boehm titration method and adsorption of acetic acid. The results show that the prepared activated carbon has a microstructure and a higher specific surface area (1179 m2/g), suggesting that the acid treatment has a significant positive influence on its sorption properties. The maximum adsorption capacity and pollutant elimination efficiency are found to be 43.48 mg/g and 90%, respectively. These results suggest that this low cost agent is an efficient tool to remove organic pollutants especially imidacloprid from wastewater
Static and Dynamic Properties of a Viscous Silica Melt Molecular Dynamics Computer Simulations
We present the results of a large scale molecular dynamics computer
simulation in which we investigated the static and dynamic properties of a
silica melt in the temperature range in which the viscosity of the system
changes from O(10^-2) Poise to O(10^2) Poise. We show that even at temperatures
as high as 4000 K the structure of this system is very similar to the random
tetrahedral network found in silica at lower temperatures. The temperature
dependence of the concentration of the defects in this network shows an
Arrhenius law. From the partial structure factors we calculate the neutron
scattering function and find that it agrees very well with experimental neutron
scattering data. At low temperatures the temperature dependence of the
diffusion constants shows an Arrhenius law with activation energies which
are in very good agreement with the experimental values. With increasing
temperature we find that this dependence shows a cross-over to one which can be
described well by a power-law, D\propto (T-T_c)^gamma. The critical temperature
T_c is 3330 K and the exponent gamma is close to 2.1. Since we find a similar
cross-over in the viscosity we have evidence that the relaxation dynamics of
the system changes from a flow-like motion of the particles, as described by
the ideal version of mode-coupling theory, to a hopping like motion. We show
that such a change of the transport mechanism is also observed in the product
of the diffusion constant and the life time of a Si-O bond, or the space and
time dependence of the van Hove correlation functions.Comment: 30 pages of Latex, 14 figure
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