The Eastward Enlargement of the Eurozone: Trade and FDI

Trade and FDI, Economic Integration

Stabilized jellium model and structural relaxation effects on the fragmentation energies of ionized silver clusters

Using the stabilized jellium model in two schemes of `relaxed' and `rigid', we have calculated the dissociation energies and the fission barrier heights for the binary fragmentations of singly-ionized and doubly-ionized Ag clusters. In the calculations, we have assumed spherical geometries for the clusters. Comparison of the fragmentation energies in the two schemes show differences which are significant in some cases. This result reveals the advantages of the relaxed SJM over the rigid SJM in dynamical processes such as fragmentation. Comparing the relaxed SJM results and axperimental data on fragmentation energies, it is possible to predict the sizes of the clusters just before their fragmentations.Comment: 9 pages, 12 JPG figure

The Anomalous Hall effect in re-entrant AuFe alloys and the real space Berry phase

The Hall effect has been studied in a series of AuFe samples in the re-entrant concentration range, as well as in the spin glass range. The data demonstrate that the degree of canting of the local spins strongly modifies the anomalous Hall effect, in agreement with theoretical predictions associating canting, chirality and a real space Berry phase. The canonical parametrization of the Hall signal for magnetic conductors becomes inappropriate when local spins are canted.Comment: 4 pages, 1 eps figur

Tunneling spectroscopy of the superconducting state of URu2Si2

We present measurements of the superconducting gap of URu$_2$Si$_2$ made with scanning tunneling microscopy (STM) using a superconducting tip of Al. We find tunneling conductance curves with a finite value at the Fermi level. The density of states is V shaped at low energies, and the quasiparticle peaks are located at values close to the expected superconducting gap from weak coupling BCS theory. Our results point to rather opened gap structures and gap nodes on the Fermi surface

Transmission of signals using white LEDs for VLC applications

In this paper an integrated wavelength optical filter and photodetector for Visible Light Communication (VLC) is used. The proposed application uses indoor warm light lamps lighting using ultra-bright white LEDs pulsed at frequencies higher than the ones perceived by the human eye. The system was analyzed using two different types the white LEDs, namely, phosphor and trichromatic based LEDs. The signals were transmitted into free space and the generated photocurrent was measured by the pin-pin photodetector based on a-SiC:H/a-Si:H. This device operates in the visible spectrum, allowing thus the detection of the pulsed white light emitted by the LEDs. However, as it also works as a visible optical filter with controlled wavelength sensitivity through the use of adequate optical biasing light, it is able to detect different wavelengths. This feature allows the detection of the individual components of the tri-chromatic white LED, which enlarges the amount of information transmitted by this type of white LED, when compared to the phosphor based LED. A capacitive optoelectronic model supports the experimental results and the physical operation of the device. A numerical simulation is presented.info:eu-repo/semantics/publishedVersio

Occurrence and relative abundance of common\ud dolphins in three sites of the Portuguese shore

Throughout the years some researchers have dedicated their efforts to the study of cetaceans’\ud occurrence off Portugal mainland. However, it is still missing a systemic scientific methodology\ud for studying the presence of coastal small cetaceans. This work is a recent approach to the\ud occurrence and relative abundance estimative of cetaceans and especially common dolphins off\ud the west central coast of Portugal. Boat-based visual surveys were conducted in three different\ud geographic locations, resulting in the sighting of several species. In Nazaré we have only\ud observed Delphinus delphis while in Peniche and Sesimbra a great diversity of species was\ud recorded, including Tursiops truncatus, Stenella coeruleoalba, Phocoena phocoena and\ud Balaenoptera acutorostrata. Most frequently sighted was common dolphin (62%). Occurrence\ud of large groups of this species seems to take place along main ocean topographic features, like\ud the Portuguese submarine canyons and we consider that great depths near shore are suitable\ud habitats for more pelagic species of dolphins such as common dolphins. Total index of common\ud dolphin abundance was of 2.198 individuals per surveyed hour. A much smaller APUE was\ud found for Peniche than for the other two regions, where common dolphins show a similar\ud relative abundance. Future studies using linear transects and continuous long-term approaches\ud will give further insight to small cetaceans’ occurrence along Portugal mainland and its relation\ud with different oceanographic features, particularly depths and distances to shore. On-going\ud efforts in coming years added to this first approach will be required to obtain knowledge for the\ud conservation of cetaceans