Spin dynamics in the Cu(2)-O planes of tetragonal and orthorhombic YBa2Cu3O7-delta as probed by 89Y NMR

The 89Y-nuclear relaxation rate is found to be almost similar in the orthorhombic and tetragonal modifications of YBa2Cu3O7-d. This result is seen as evidence for the unchanged spin dynamics in the Cu(2)-O planes in both compounds and as support for those theories that decouple charge and spin carriers

The conductivity and band structure of some synthetic semiconductors based on M(dmit)2 (M = Ni, Pd, Pt)

The conductivity of the following six new low-dimensional compounds is reported: (Me4N)(Ni(dmit)2), (Et4N)(Ni(dmit)2), (Pr4N)(Ni(dmit)2), (Bu4N)(Ni(dmit)2), (Bu4N)(Pt(dmit)2) and (Et4N)0.5(Pd(dmit)2). Semiconducting behaviour is found for all the compounds investigated, with activation energies between 0.1 and 0.5 eV. The crystal structures have been established by X-ray diffraction. Using these, the band structure has been determined. It is shown that the compounds investigated are semiconductors each having a correlation gap resulting from an effective electron-electron repulsion of 1.0 eV

Spin dynamics in the Cu(2)-O planes of tetragonal and orthorhombic YBa2Cu3O7-delta as probed by 89Y NMR

The 89Y-nuclear relaxation rate is found to be almost similar in the orthorhombic and tetragonal modifications of YBa2Cu3O7-d. This result is seen as evidence for the unchanged spin dynamics in the Cu(2)-O planes in both compounds and as support for those theories that decouple charge and spin carriers

The conductivity and band structure of some synthetic semiconductors based on M(dmit)2 (M = Ni, Pd, Pt)

The conductivity of the following six new low-dimensional compounds is reported: (Me4N)(Ni(dmit)2), (Et4N)(Ni(dmit)2), (Pr4N)(Ni(dmit)2), (Bu4N)(Ni(dmit)2), (Bu4N)(Pt(dmit)2) and (Et4N)0.5(Pd(dmit)2). Semiconducting behaviour is found for all the compounds investigated, with activation energies between 0.1 and 0.5 eV. The crystal structures have been established by X-ray diffraction. Using these, the band structure has been determined. It is shown that the compounds investigated are semiconductors each having a correlation gap resulting from an effective electron-electron repulsion of 1.0 eV

Towards a CE mark for PV building integrated systems

The European projects Prescript and Precede aim to pave the way for the development of a procedure to obtain a CE mark for building integrated PV. Prescript has carried out a survey of national building standards and performaed a series of tests on BIPV systems. Prescript has resulted in a proposal for a pre-standard for testing BIPV systems. Procede aims to develop a CE mark for BIPV system via the development of a European Technical Approval Guideline. The guideline will be developed, after a mandate of te EC has been given, in close co-operation with PV industy in the European countrie

High titres of pre-existing adenovirus serotype-specific neutralizing antibodies predict viral reactivation after allogeneic stem cell transplantation in children

Transplantation and immunomodulatio