Diffusion Activation Energy and Desorption Activation Energy for Astrochemically Relevant Species on Water Ice Show No Clear Relation

Surface diffusion: the low activation energy path for nanotube growth.

We present the temperature dependence of the growth rate of carbon nanofibers by plasma-enhanced chemical vapor deposition with Ni, Co, and Fe catalysts. We extrapolate a common low activation energy of 0.23-0.4 eV, much lower than for thermal deposition. The carbon diffusion on the catalyst surface and the stability of the precursor molecules, C2H2 or CH4, are investigated by ab initio plane w...

Activation energy for water diffusion across the toad bladder: evidence against the pore enlargement hypothesis.

The activation energy (E(A)) for the diffusion of water across the epithelial cell layer of the toad bladder was determined in the absence and presence of vasopressin. An experimental approach was employed which minimized the effects of unstirred layers and the thick supporting layer of the bladder on the measurement of water diffusion. E(A) in the absence of vasopressin was 11.7 +/-1.4 kcal.mo...

Activation entropy, activation energy, and magnetic viscosity

CuMn2O4 nanostructures: Facial synthesis, structural,magnetical, electrical characterization and activation energy calculation

The work is the report about stearic acid sol-gel synthesis method, magnetically, electricalcharacterization and activation energy of copper manganese oxide nanostructures. The CuMn2O4 nanostructures are synthesized at a temperature of 600°C using the sol-gel method. The structural analysis using X-ray diffraction (XRD) and Scherrer equation show that the crystallite size of CuMn2O4 is ab...

Adsorption of Astrochemically Relevant Molecules on Interstellar

In the last few decades, astronomers have found that interstellar clouds are chemical factories, in which atoms are processed into more complex chemical species in reactions energized by starlight and fast particles. Many of the identified molecules are formed in networks of ion-molecule and neutral-neutral reactions and, at the low temperatures in the interstellar medium (-15 K), can accrete o...