Coverage-dependent sticking probabilities and second-order rate constants for recombinative desorption of hydrogen from Rh( 111 ) have been measured using molecular beam relaxation spectroscopy (MBRS) and time-resolved specular helium scattering. The sticking probability follows second-order Langmuir coverage dependence, with So equal to 0.01 ___ 0.005. Under isothermal and nearly isosteric con...

The ingestion of volcanic ash by jet engines is widely recognized as a potentially fatal hazard for aircraft operation. The high temperatures (1,200-2,000 °C) typical of jet engines exacerbate the impact of ash by provoking its melting and sticking to turbine parts. Estimation of this potential hazard is complicated by the fact that chemical composition, which affects the temperature at which v...

By performing six-dimensional quantum-dynamical calculations on potential energy surfaces derived from density Ž . Ž . functional theory total-energy calculations, we have determined the sticking probability of H on Rh 100 , Pd 100 and 2 Ž . Ag 100 . In particular, we have focused on the dependence of the sticking probability on the initial rotational state of the impinging hydrogen beam. The d...

In a 69 year old woman with a "sticking" Björk-Shiley mitral prosthesis, the diagnosis was suggested by both the two-dimensional and the Doppler ultrasound examinations. In particular, the findings of early diastolic paradoxic septal motion, intermittent delayed opening of the prosthetic disc and variable timing of the onset of mitral valve inflow were believed to be diagnostic of a sticking ti...

In studies reported earlier, interference with the clotting of blood in vivo failed to prevent the vigorous sticking of leucocytes to vascular endothelium within rabbit ear chambers damaged by heat. As a specific example, maximal activation of the endogenous fibrinolytic system of rabbits by streptokinase (SK) administration did not diminish adherence of circulating white blood cells to endothe...

The kinetics of the adsorption of NH3 on W(110) and its subsequent dissociation have been investigated using molecular beam techniques and temperature programmed desorption (TPD) for surface temperatures ranging from 140 to 700 K. NH3 shows a wide desorption peak around 270 K and a smaller peak at 170 K while H2 and N2, produced by dissociation, desorbed at 550 K and 1350 K, respectively, with ...