A theoretical study at the B3LYP/6-31++G(d,p) level was performed on the tatumerization of 7H-purine-2, 6-diamine into 9H-purine-2, 6-diamine. Such a tautomerism can take place via three different pathways namely A, B, and C. The energetic results associated with the gas phase reveal that pathways A, B, and C display a very high activation Gibbs free energy of 45.1, 68.6 and 48.9 kcal/mol, resp...

the effect of mechanical activation on structural changes and kinetics of carbothermic reduction of hematite with graphite was studied in this research. hematite powder mixture with graphite (with stoichiometry ratio c/o=1) was milled for the time periods of zero to 50 hours, and the structural changes were studied using x ray diffraction (xrd). the effect of mechanical activation on the kineti...

The effect of mechanical activation on structural changes and kinetics of carbothermic reduction of hematite with graphite was studied in this research. Hematite powder mixture with graphite (with stoichiometry ratio C/O=1) was milled for the time periods of zero to 50 hours, and the structural changes were studied using X ray diffraction (XRD). The effect of mechanical activation on the kineti...

energy and mass transfer investigations in thermal processing of fruits serve as a breakthrough in the design and scale up of drying systems. diffusivity characteristics and specific energy consumption for drying of fig fruit in a laboratory scale microwave dryer were assessed. several intervals for microwave power intensity including 0.5, 1, 1.5, 2, and 2.5 w g-1, and 6 levels of power on-off ...

jujube (zizyphus jujube mill), a valuable medicinal plant, is consumed either as fresh fruit or dried product in iran. drying jujube guarantees a longer shelf time while preserving its quality to be used in medical and pharmaceutical industries. in this research paper, the influence of several drying conditions on the effective moisture diffusivity, activation energy, energy consumption and req...

  The flux-pinning mechanism and activation energy of 10 wt % malic acid-doped MgB2 were investigated by measuring of the critical current density and resistivity as a function of magnetic field and temperature. A crossover field, Bsb, was observed from the single vortex to the small vortex bundle pinning regime. For the sintered sample, the temperature dependence of Bsb(T) at low temperature i...

the canola drying process was investigated using three laboratory scale dryers connected to a computer which continuously recorded the drying processes of each unit. a completely randomized design (crd) with three replications was used for the statistical analysis. the effect of temperature (40°, 50°, 60°c) and air velocity (1, 2 m/s) on the drying kinetics of a monolayer were studied. the effe...