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The unoccupied π* bands of epitaxial overlayers of benzene, naphthalene, anthracene, tetracene, perylene, and coronene on a Ag(111) surface have been studied by angle resolved inverse photoemission spectroscopy. A comparison with HAM/3 MO calculations and electron transmission gas phase measurements enables the assignment of the π* affinity levels of these organic systems. In conjunction with previous angle resolved photoemission, optical absorption, and near edge x-ray absorption studies a complete picture of their valence band structure and morphology evolves. Optical and x-ray absorption excitation energies are discussed in the light of the experimentally determined one-electron correlation diagram. Gas phase–solid relaxation energies of the affinity levels are found to decrease in the series of benzene to tetracene (1.7→0.5 eV) attributed to the increasing size of the involved molecular orbitals. For benzene a low lying σ*-shape resonance has been identified in the isochromat inverse photoemission spectrum.

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For a diabetes mellitus patient, tight control of glucose level is essential. Results are reported of an investigation of the suitability of existing wearable continuous insulin infusors controlled and adjusted by a control algorithm using continuous glucose measurements as input to perform the functionality of an artificial pancreas. Special attention was given to the development of a continuous glucose monitor and to evaluate which quality of input data is necessary for the control algorithm. In clinical trials, it was found that for patients in a controlled environment an autonomously regulating control algorithm leads to an improved adjustment of patient glucose values and less overall insulin infusion as compared with the best fixed preprogrammed insulin infusion profiles of standard pump therapy. For the limited number of cases studied here, functionality of the control algorithm could tolerate some delay between the actual glucose values in the patient interstitial fluid and the algorithm input of up to 30 min. A quasicontinuous glucose measurement delivering actual glucose values every 5-10 min seems to be suited to control an artificial pancreas.

The electron affinity levels of condensed films of benzene, chlorobenzene, 1.4-dichlorobenzene, s-trichlorobenzene, and hexafluorobenzene on Cu(111) have been determined by isochromat inverse photoemission spectroscopy. In addition to the π* orbitals of the benzene ring, low-lying σ* orbitals are observed in the chlorine and fluorine-substituted molecules. Comparison to electron transmission spectra allows the assignment of the unoccupied molecular orbitals and the determination of the relaxation energies in going from the gas phase to the solid state. These relaxation energies are found to decrease in the series of benzene to trichlorobenzene.

We have determined the unoccupied part of the electronic structure of sodium on Cu(111), employing k-resolved inverse photoemission in the isochromat mode. For Na coverages above 0.15 monolayer, an image-potential surface state is observed 2.3 eV above EF. For the completed p (2 X 2) Na phase at 0.25monolayer coverage, a pronounced Na3p,derived feature occurs 0.4 eV above EF, which exhibits a 0 nearly-free-electron-like energy dispersion. For wave vectors kI~~0 .6 A, the unoccupied part of the Na 3s band appears close to the Fermi level. We compare our results with recent band-structure calculations for free and adsorbed Na monolayers.