The vertical motion field in the thermosphere is calculated from the continuity equation. This calculation ik based on a field of horizontal winds and an intermediate model of the thermospheric temperature field consistent with the density structure inferred from satellite drag data. The vertical motion consists of a component due to rise and fall of constant pressure surfaces and a component d...

The effect of deformation by nanoindentation on nanocrystallization in amorphous Al90Fe5Gd5 was investigated by transmission electron microscopy. Massive precipitation of nanocrystallites is observed within the indents. Under the quasistatic condition used, a temperature rise due to adiabatic heating is likely negligible, confirming that plastic deformation can induce crystallization without a ...

The universe is filled with nearly isotropic cosmic microwave background (CMB) radiation, which has a blackbody spectrum of temperature T ≈ 2.73K. In addition, there are tiny direction dependent deviations δT from the mean temperature, δT/T . 10−4. These CMB anisotropies result from small primordial perturbations. The initial conditions, deep in the radiation-dominated universe, can be a mixtur...

Nomenclature a = stoichiometric coefficient av = surface-to-volume ratio C;, Cb; = surface and bulk concentration, vol % Da = Damkohler number Eif R = activation energy, K F = steady-state function h = heat-transfer coefficient K, = adsorption equilibrium coefficient k, k0 = reaction rate constant and preexponential factor, respectively kc = mass-transfer coefficient l = apparent reaction order...

downbursts are small-scale, short-lived and energetic events in the atmosphere. they usually occur from the beginning of spring to summer when the weather is more humid and the convective weather conditions are suitable. because of the small-scale property of the downburst, it has sometimes been observed only in a meteorological station and other stations have not observed considerable changes....

ethyl benzene used increasingly each year is the raw material of producing styrene monomer. this substanceis produced from benzene alkylation with ethylene or ethanol, depending on the availability and cost of rawmaterials. in this study benzene alkylation in the presence of ethanol in a catalytic fixed bed reactor inthree states of isotherm, adiabatic and non-isotherm-non-adiabatic is mathemat...

To understand the plastic ̄ow behavior of commercially pure vanadium under high strain rates, uniaxial compression tests of cylindrical samples are performed using UCSD's enhanced Hopkinson technique. True strains exceeding 50% are achieved in these tests, over a range of temperature from 77 to 800 K at the strain rates of 2500 and 8000 sÿ1. The microstructure of the deformed and undeformed sam...

Electrons can experience super-adiabatic heating at a collisionless shock due to the presence of a cross-shock electric potential. This heating can greatly exceed the temperature rise associated with the conservation of the magnetic moment of the electrons as they move into the stronger magnetic eld downstream of the shock. The criterion for the onset of super-adiabatic heating and the eeects o...