2005
Authors
Oliveira, L; Lage, A;
Publication
Saratov Fall Meeting 2004: Optical Technologies in Biophysics and Medicine VI
Abstract
Computational methods have been used with great application to biomedical optics. The events created by the interaction of radiation with biological materials can easily be translated to computer languages with the objective of producing simulation techniques to be used prior to physical intervention. The addition of biocompatible and hyper osmotic agents to several types of biological tissues has proven the enhancement of transparency to radiation flux by reduction of material's optical properties. The evolutionary behavior of the agent's action in the tissue samples before saturation has been observed by numerous researchers but has never been described mathematically. In the present work we will describe the application of Monte Carlo simulation to estimate the evolutionary states of optical transparency of biological tissues when immersed in an osmotic solution. We begin our study with typical values for the optical properties of rabbit muscle and proceed by reducing the absorption and scattering coefficients independently and simultaneously. The results show the number of transmitted, absorbed, scattered and reflected photons in different stages of the action of a generic osmotic agent over a small and well defined tissue sample.
2005
Authors
Ribeiro, H; Cunha, M; Abreu, I;
Publication
ANNALS OF AGRICULTURAL AND ENVIRONMENTAL MEDICINE
Abstract
The aim of this work was to study spatial and temporal distribution of Olea europeae airborne pollen in different Portuguese regions: Reguengos de Monsaraz (south); Bairrada (west): Braga (northwest); Valenca do Douro and Foz Coa (northeast). Airborne pollen sampling was conducted from 1998-2003 using "Cour" type samplers located in each region. The main pollen season (NIPS) of Olea lasted on average 36 days and occurred from late April until middle-to-end of June. During the studied period, inter-annual variations among and within regions, concerning the total annual pollen counts and the beginning, peak and ending dates of the MPS. were reported. Reguengos de Monsaraz and Bairrada registered the earliest MPS starting date, followed by Valenca do Douro and Foz-Coa, and the latest date was verified in Braga that also had the shortest MPS. Reguengos de Monsaraz presented the longest MPS with the highest differences in the beginning and ending dates, but minimum differences in the dates of the maximum pollen peak. Our results showed an increase in the Olea annual pollen index, from north to south. and from the west to the east regions of the country.
2005
Authors
Marques, P; Castro, H; Ricardo, M;
Publication
IEEE WIRELESS COMMUNICATIONS
Abstract
Foreseeing a future where IPv6 and mobile terminals play an important role in public access communication networks, this article introduces a monitoring system capable of identifying relevant traffic flows and tracking them while terminal equipment moves between network attachment points. The mobile flows are characterized and represented so that individual users and flows can perceive the quality of service they receive, and operators can have global traffic views of their heterogeneous access networks.
2005
Authors
Mamede, J; Carrapatoso, E; Ricardo, M;
Publication
AC 2005, Proceedings of the IADIS International Conference on Applied Computing, Algarve, Portugal, February 22-25, 2005, 2 Volumes
Abstract
2005
Authors
Mardare, AI; Mardare, CC; Fernandes, JRA; Moreira, JA; Marques, MB;
Publication
JOURNAL OF PHYSICS-CONDENSED MATTER
Abstract
The bottom electrode crystallization method was used for the heat-treatment of amorphous Pb(Zr-0(52)., Ti-0.48)O-3 thin films deposited by radio-frequency magnetron sputtering on Pt/Ti/SiO2/Si substrates. Two different heating and cooling rates were applied and two different contact wires (W and Pt) were alternately used for the Joule heat generation in the Pt bottom electrode. The dielectric and ferroelectric properties of the films were compared with the properties of the films crystallized using halogen lamp annealing in the same conditions. All the PZT samples showed similar ferroelectric properties at room temperature, with high dielectric constant and remanent polarization values as well as good resistance to ferroelectric fatigue, the Al/PZT/Pt/Ti/SiO2/Si capacitors having low leakage currents. The experimental results obtained show that the bottom electrode crystallization method is a cheap and low power consumption method which can successfully replace the classical crystallization methods.
2005
Authors
Camacho, R; Alves, A; da Costa, JP; Azevedo, P;
Publication
PROGRESS IN ARTIFICIAL INTELLIGENCE, PROCEEDINGS
Abstract
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