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About


Maria Inês Carvalho graduated in Electrical and Computer Engineering from the University of Porto in 1990 and received her M.S. and Ph.D. degrees in Electrical Engineering from Lehigh University, USA, in 1994 and 1996, respectively. She joined the Electrical and Computer Engineering Department at the University of Porto in 1996 as an assistant professor, where she is presently an associate professor. In 2009 she joined INESC TEC as a researcher. Her main research area has been the propagation of light in nonlinear media. Her work includes both the theoretical modeling of these phenomena and their numerical simulation and has addressed, among others, soliton beams in photorefractive media, incoherent solitons and microstructured optical fibers. She is a member of the Optical Society of America.

Interest
Topics
Details

Details

003
Publications

2018

Evaluation of SAR induced by a planar inverted-F antenna based on a realistic human model

Authors
Vieira, VF; Pessoa, LM; Carvalho, MI;

Publication
IFMBE Proceedings

Abstract
In this paper the absorption by the human body of electromagnetic (EM) radiation generated by a Planar Inverted-F Antenna (PIFA) from a modern mobile phone is investigated through the evaluation of the Specific Absorption Rate (SAR) in head, brain and hand regions using Sim4Life (S4L) and a realistic anatomical model. Several scenarios were evaluated, by varying the distance between the antenna and the head, the feeder position and the orientation of the antenna. The effect of the presence of the hand was also studied and, finally, different communication bands were considered. The main results show that the presence of the hand is determinant to reduce SAR on head and brain, while bottom orientations of the antenna reduce the SAR on the brain, but increase the SAR in other tissues. © Springer Nature Singapore Pte Ltd. 2018.

2017

Plain and oscillatory solitons of the cubic complex Ginzburg-Landau equation with nonlinear gradient terms

Authors
Facao, M; Carvalho, MI;

Publication
PHYSICAL REVIEW E

Abstract
In this work, we present parameter regions for the existence of stable plain solitons of the cubic complex Ginzburg-Landau equation (CGLE) with higher-order terms associated with a fourth-order expansion. Using a perturbation approach around the nonlinear Schrdinger equation soliton and a full numerical analysis that solves an ordinary differential equation for the soliton profiles and using the Evans method in the search for unstable eigenvalues, we have found that the minimum equation allowing these stable solitons is the cubic CGLE plus a term known in optics as Raman-delayed response, which is responsible for the redshift of the spectrum. The other favorable term for the occurrence of stable solitons is a term that represents the increase of nonlinear gain with higher frequencies. At the stability boundary, a bifurcation occurs giving rise to stable oscillatory solitons for higher values of the nonlinear gain. These oscillations can have very high amplitudes, with the pulse energy changing more than two orders of magnitude in a period, and they can even exhibit more complex dynamics such as period-doubling.

2017

Skeletal muscle dispersion (400-1000?nm) and kinetics at optical clearing

Authors
Oliveira, LM; Carvalho, MI; Nogueira, EM; Tuchin, VV;

Publication
Journal of Biophotonics

Abstract

2016

Optical clearing mechanisms characterization in muscle

Authors
Oliveira, L; Carvalho, MI; Nogueira, E; Tuchin, VV;

Publication
JOURNAL OF INNOVATIVE OPTICAL HEALTH SCIENCES

Abstract
Optical immersion clearing is a technique that has been widely studied for more than two decades and that is used to originate a temporary transparency effect in biological tissues. If applied in cooperation with clinical methods it provides optimization of diagnosis and treatment procedures. This technique turns biological tissues more transparent through two main mechanisms - tissue dehydration and refractive index (RI) matching between tissue components. Such matching is obtained by partial replacement of interstitial water by a biocompatible agent that presents higher RI and it can be completely reversible by natural rehydration in vivo or by assisted rehydration in ex vivo tissues. Experimental data to characterize and discriminate between the two mechanisms and to find new ones are necessary. Using a simple method, based on collimated transmittance and thickness measurements made from muscle samples under treatment, we have estimated the diffusion properties of glucose, ethylene glycol (EG) and water that were used to perform such characterization and discrimination. Comparing these properties with data from literature that characterize their diffusion in water we have observed that muscle cell membrane permeability limits agent and water diffusion in the muscle. The same experimental data has allowed to calculate the optical clearing (OC) efficiency and make an interpretation of the internal changes that occurred in muscle during the treatments. The same methodology can now be used to perform similar studies with other agents and in other tissues in order to solve engineering problems at design of inexpensive and robust technologies for a considerable improvement of optical tomographic techniques with better contrast and in-depth imaging.

2015

Temporal dissipative solitons in a three-level atomic medium confined in a photonic-band-gap fiber

Authors
Facao, M; Rodrigues, S; Carvalho, MI;

Publication
PHYSICAL REVIEW A

Abstract
We obtained a propagation equation for an optical pulse at an electromagnetically induced transparency window guided on a gas-filled hollow-core photonic crystal fiber. This equation admits dissipative solitons whose analytical expression was also obtained. Depending on the parameter region, they may be stable or unstable. We simulated a typical experimental arrangement and found some cases for which the equation parameters are such that it admits stable solitons.

Supervised
thesis

2017

Effect of electromagnetic fields induced by mobile devices in the human brain

Author
Vânia Filomena Madureira Vieira

Institution
UP-FEUP

2016

Optical characterization of atmospheric turbulence

Author
Paulo Alexandre Paiva de Andrade

Institution
UP-FEUP