Search

Sb doped Sn02 has been deposited on polished ceramic A1203 substrates by Pulsed Laser Deposition. Conductivity, charge carrier density and mobility of these thin films have been meas ured as a function of temperature. A model for the electrical properties of the films is proposed. Since Sb doped Sn02 is a transparent, high mobility material, it is shown that it can be used as channel material for an all-oxide thin film transparent field-effect transistor with a linear dielectric.

Permanent magnets which show the highest magnetic flux density, have been used in constructing an insertable Permanent Magnetic Quadrupole (PMQ). The PMQ is part of an electron irradiation facility for polymer research at the Eindhoven University of Technology. For polymer irradiation that requires a homogeneous dose distribution, the PMQ is inserted and the expanded electron beam will irradiate the target completely. Design criteria of the quadrupole are discussed. The quadrupole geometry has been optimised using CEDRAT finite element software. The influence of mechanical alignment errors (0.15 mm) and variations in permanent magnet properties (0.5%) on the magnetic field have been simulated. Sixteen NdFeB magnets (42x42x10 mm3) have been used to produce a quadrupole with an aperture radius of 50 mm. Before insertion, the magnetic flux density of all magnets has been determined versus magnetic field and temperature. After construction the lens strength of the quadrupole has been determined using the floating wire technique. The flux density has been measured using a Hall probe. Results show a magnetic field gradient that varies less than 0.5% within a radius of 25 mm. Alignment errors have been determined comparing simulation and measurement.

Based on the two-level squaring construction of the Reed-Muller code, a bounded-distance decoding algorithm for the Nordstrom-Robinson code is given. This algorithm involves 199 real operations, which is less than one half of the computational complexity of the known maximum-likelihood decoding algorithms for this code. The algorithm also has exactly the same effective error coefficient as the maximum-likelihood decoding, so that its performance is only degraded by a negligible amount.

Recent advances in the field of reactive and inelastic schattering of electronically excited rare gas atoms in metastable R*{(np)5(n+1)s} and shortlived R**{(np)5(n+1)p} states are discussed in case studies of the relevant processes: excimer formation, excitation transfer, Penning ionization and intramultiplet mixing. For reactive scattering the fine structure dependence of (KrBr) excimer formation is studied, showing that the propensity for core state conservation depends strongly on the halogen donor used. As a prototype of excitation transfer collisions the Ar*(3P0,2)–N2 system is analysed with respect to electronic, vibrational and rotational excitation. Vibrational excitation is well understood in terms of a Landau Zener type semiclassical model: the two observed rainbow singularities in the rotational distribution lead to a classical description of scattering on a hard shell with both a P2–and a P4–anisotropy. For Penning ionization new insight is given for the well-studied Ne*(3P0,2)–Ar system. Ab-initio calculations of the auto-ionization width confirm the validity of a simple two-state basis model for the metastable states. Polarisation effects in the ionization cross section for the Ne**(3p)–Ar system are used to establish a practical semiclassical criterion for ‘‘locking’’ of the total electronic angular momentum to the internuclear axis. Finally, intramultiplet mixing is discussed for the Ne**(3p)–He system. The observed polarised-atom cross sections are in good agreement with quantum mechanical coupled channel calculations, using the model potentials of Hennecart and Masnow-Seeuws as input. The results are equally well described with a semiclassical model that incorporates both rotational and radial coupling.

No abstract.

No abstract.

The main objective of the CHIP project is to demonstrate how Semantic Web technologies can be deployed to provide personalized access to digital museum collections. We illustrate our approach with the digital database ARIA of the Rijksmuseum Amsterdam. For the semantic enrichment of the Rijksmuseum ARIA database we collaborated with the CATCH STITCH project to produce mappings to Iconclass, and with the MultimediaN E-culture project to produce the RDF/OWL of the ARIA and Adlib databases. The main focus of CHIP is on exploring the potential of applying adaptation techniques to provide personalized experience for the museum visitors both on the Web site and in the museum.