Interaction, Neighborhood Selection and Housing Demand

social interactions, neighborhood selection, housing, neighborhood effects

Vortex states in patterned exchange biased NiO/Ni samples

We investigated the magnetization reversal of arrays of exchange biased NiO/Ni squares with superconducting quantum interference device magnetometry and micromagnetic simulations. The edges of the squares were 0.5, 1.5, and 3.0 $\mu$m long. The NiO/Ni structures exhibit vortexlike hysteresis loops and micromagnetic calculations show that this feature is due to several vortices nucleating in the islands. Furthermore, for the arrays with squares of 1.5 $\mu$m edge length, the sign of the exchange bias field changes, as compared to the same continuous NiO/Ni layer. We attribute the vortex nucleation and the change of the exchange bias field to the interplay between shape and unidirectional anisotropy.Comment: 6 pages, 7 figure

The search for stem cells of the epithelium in pulmonary alveoli

In recent years significant progress has been witnessed in the identification of stem cells, which have now also been identified in the lungs. The aim of this was to induce post-pneumonia alveolar regeneration to facilitate the identification of stem cells. The studies were performed on Buffalo strain rats. Pneumonia was induced in the animals by a sub-pleural injection of carragenin. On days 4, 5 and 10 of the experiment both the control and experimental animals received intraperitoneal injections of bromodeoxyuridine (BrdU). Twenty-four hours after the last BrdU injection the rats were sacrificed and samples of the lungs were taken for examination. In order to detect proliferating cells in the paraffin sections, BrdU incorporation was detected with monoclonal antibodies. In pilot experiments BrdU incorporation was demonstrated in individual alveolar cells of variable distribution and of variable intensity in the colour reaction. The results have confirmed the existence of stem cells in pulmonary alveoli but their closer characterisation requires further studies with other techniques to detect pulmonary stem cells

CALCOM'10 Sea Trial - field calibration data report

Rep 04/10 - SiPLAB November/2010The CALCOM'10 sea trial took place in a region SSE of Vilamoura from 22nd to 24th June to support WEAM & PHITOM projects. The rst day was devoted to equipment testing and calibration. The second and third days were devoted to eld calibration and underwater communications. This report refers to eld calibration data acquired 23rd June, Day 2, and 24th June, Day 3

Acoustic oceanographic buoy data report Makai Ex 2005

Rep 04/05 - SiPLAB 17/Nov/2005 UniversityIt is now well accepted in the underwater acoustic scientific community that below, say, 1 kHz acoustic propagation models are accurate enough to be able to predict the received acoustic field up to the point of allowing precise and reliable source tracking in range and depth with only limited environmental information. This results from a large number of studies both theoretical and with real data, carried out in the last 20 years. With the event of underwater communications and the necessity to increase the signal bandwidth for allowing higher communication rates, the frequency band of interest was raised to above 10 kHz. In this frequency band the detailed knowledge of the environment - acoustic signal interplay is reduced. The purpose of the MakaiEx sea trial is to acquire data in a complete range of frequencies from 500 Hz up to 50 kHz, for a variety of applications ranging from high-frequency tomography, coherent SISO and MIMO applications, vector - sensor, active and passive sonar, etc...The MakaiEx sea trial, that took place off Kauai I. from 15 September - 2 October, involved a large number of teams both from government and international laboratories, universities and private companies, from various countries. Each team focused on its specific set of objectives in relation with its equipment or scientific interest. The team from the University of Algarve (UALg) focused on the data acquired by their receiving Acoustic Oceanographic Buoy - version 2 (AOB2) during six deployments in the period 15 - 27 September. This report describes the AOB2 data set as well as all the related environmental and geometrical data relative to the AOB2 deployments. The material described herein represents a valuable data set for supporting the research objectives of projects NUACE1, namely to fulfill NUACE’s task 3 and 4 and RADAR2, namely its tasks 2 and 3 devoted to the developement and testing of a field of sonobuoys.This report presents the testing of the most recent version of the Acoustic Oceanographic Buoy (AOB) system and the results obtained during the Makai Ex sea trial. The MakaiEx sea trial took place off the west coast of Kauai I., Hawaii, USA, in the period September 15 - 27, 2005. The authors of this report would like to thank: • all the personnel involved, including R/V Kilo Moana crew • the scientist in charge Michael B. Porter • the University of Hawaii for its support • FCT (Portugal) for the funding provided under projects NUACE (POSI/CPS/47824/ 2002) and RADAR (POCTI/CTA/47719/2002). • ONR for the funding under ONR-IFO VSP grant # N00014-04-1-403

Enhanced photoluminescence emission from two-dimensional silicon photonic crystal nanocavities

We present a temperature dependent photoluminescence study of silicon optical nanocavities formed by introducing point defects into two-dimensional photonic crystals. In addition to the prominent TO phonon assisted transition from crystalline silicon at ~1.10 eV we observe a broad defect band luminescence from ~1.05-1.09 eV. Spatially resolved spectroscopy demonstrates that this defect band is present only in the region where air-holes have been etched during the fabrication process. Detectable emission from the cavity mode persists up to room-temperature, in strong contrast the background emission vanishes for T > 150 K. An Ahrrenius type analysis of the temperature dependence of the luminescence signal recorded either in-resonance with the cavity mode, or weakly detuned, suggests that the higher temperature stability may arise from an enhanced internal quantum efficiency due to the Purcell-effect