[en] The principles, variable parameters and potential information underlying experiments which involve the scattering of neutral particles with thermal kinetic energies at metal surfaces are briefly outlined. A few examples for the application of ground-state particles are presented: Diffractive scattering, studies on the kinetics of adsorption and desorption as well as reactive scattering. Scattering of electronically excited particles may give rise to electron emission as is demonstrated for metastable He-atoms impinging on clean and adsorbate covered Pd surfaces. Analysis of the electron density distributions yields information on the valence electron states of the outmost layers. (Auth.)

[en] The oxidation of polycrystalline samples of Ni/Pd-alloys at 600⁰C and 2 x 10^-5 Torr O₂ has been investigated by means of Auger electron spectroscopy and soft X-ray appearance potential spectroscopy. The clean surfaces are enriched by Pd; and with increasing Pd content the binding energy of the Ni 2p-core levels was found to decrease continuously by 0.7 eV. After completion of the oxidation identical overlayers were formed on all samples (except on pure Pd) which were identified to consist of NiO. Within the depth probed by the applied techniques (approximately < 20 A) the rate of oxidation was found to increase with increasing Pd content, which is in contrast to the behaviour to be expected for the growth of thick oxide layers after the formation of a coherent NiO overlayer. (orig.)

[en] Theoretical analysis of Surface Penning Ionization (SPI) is reported and applied to the process Hesup(*) + CO → He + CO⁺ + e^- for CO molecules adsorbed on a Pd(111) surface. Potential curves, ionization rates, and angular distributions of the emitted electrons are calculated. The results exhibit the extreme surface sensitivity of SPI and indicate its usefulness in studying the electronic and geometrical properties of adsorbates. (orig.)

[en] In this case of an 71 year old female patient the explantation of an infected pacemaker system was complicated by the fact that the infected electrode was not extracted at first but only shortened to an extent, which make further extraction along the original cephalical implantation route impossible. By combined use of a pigtail catheter and a wire loop with sheath the infected electrode was pulled into the inferior vena cava. By twisting the pigtail catheter counterclockwise the screw-in-electrode was screwed out and extracted consecutively. With this method the more perilous cardiovascular surgery including atriotomy could be avoided and the source of chronic infection could be removed permanently. (orig.)

[en] The adsorption of CO and O₂ on Pd(111) has been studied using the molecular beam technique. Absolute sticking coefficients have been measured for CO adsorption. The oxidation of CO is shown to proceed via a Langmuir-Hinshelwood (LH) mechanism: no evidence for an Eley-Rideal (ER) mechanism is seen. (Auth.)

[en] Atomic hydrogen chemisorbed on a Ni(111) surface forms at coverage between 0.3 and 0.6 an ordered 2x1-structure as observed by low energy electron diffraction (LEED). The intensity of the fractional-order LEED spots was measured at different coverages as a function of temperature. continuous order-disorder transitions are found, the maximum transition temperature (270 K) being at Theta = 0.5. The phase diagram, however, is asymmetric with respect to this coverage and can therefore presumably not be explained on the basis of (independent) pairwise interactions. (author)

[en] Adsorption of K on Fe(110), (100) and (111) surfaces was studied by means of LEED, AES, thermal desorption and work function measurements. The monolayer capacity is about 5.5 x 10¹⁴ K-atoms/cm² in all three cases. With Fe(111) an ordered 3 x 3 overlayer was found at fairly low coverages. The work function decreases to a minimum and the initial dipole moments were determined to μ₀ = 7.0 Debye for Fe(110), μ₀ = 4.4 Debye for K/Fe(100) and μ₀ = 3.9 Debye for K/Fe(111). The heat of adsorption decreases from its initial value (Fe(110): 57; Fe(100): 54; Fe(111): 52 kcal/mole) continuously with increasing coverage which parallels the continuous decrease of the dipole moment of the adsorbate complex. (orig.)

No abstract available

[en] Angular distributions of CO₂, I(γsub(r)), formed by catalytic reaction between CO and O₂ on a stepped Pt(111) surface, have been measured by means of molecular beam techniques as a function of CO and O coverages, in the presence of 'subsurface oxide', and at varying temperatures. The resulting data can well be fitted by I(γsub(r))=a cos γsub(r)+(1-a) cos⁷γsub(r) with a being an adjustable parameter which varies with the surface conditions. The cos γsub(r) part is ascribed to particles which were completely accommodated with their translational energy to the surface temperature before leaving the surface, while the cos⁷ γsub(r) channel corresponds to molecules carrying excess translational energy from crossing the activation barrier of the surface reaction. The fraction of thermally accommodated particles increases by the presence of steps or 'subsurface oxide', and decreases with O and CO coverage as well as with increasing temperature. The effect of coverage can qualitatively be attributed to the varying participation of defect sites in product formation, while the influence of surface temperature is well reproduced in the framework of a general theoretical model. Scattering experiments with CO₂ revealed that the trapping probability for this molecule of the order of 0.5, thus confirming the conclusion of incomplete thermal accommodation of a CO₂ molecule interacting with a Pt(111) surface. (orig./RK)

[en] There is some controversy whether or not nitroglycerin improves blood flow to the ischemic myocardial zone. One aspect of the study was to determine the effect of nitroglycerin on thallium-201 distribution in patients with myocardial infarction. The results suggest that nitroglycerin may improve blood flow to an ischemic zone and that thallium-201 myocardial imaging (TMI) before. and after nitroglycerin may thus indicate viability of the myocardium. It needs further investigation to prove whether this myocardial tissue may profit from bypass graft surgery. Second aspect of the study was to find a pharmacological tool to detect viable myocardium inside or around TMI defects