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Publicações

2016

Quantitative determinations and imaging in different structures of buried human bones from the XVIII-XIXth centuries by energy dispersive X-ray fluorescence - Postmortem evaluation

Autores
Guimaraes, D; Dias, AA; Carvalho, M; Carvalho, ML; Santos, JP; Henriques, FR; Curate, F; Pessanha, S;

Publicação
TALANTA

Abstract
In this work, a non-commercial triaxial geometry energy dispersive X-ray Fluorescence (EDXRF) setup and a benchtop mu-XRF system were used to identify postmortem contamination in buried bones. For two of the individuals, unusually high concentrations of Cu and Pb, but also Zn (in one individual) were observed. The pigments of the burial shroud coverings have been identified as the source of contamination. Accurate and precise quantitative results were obtained by nondestructive process using fundamental parameters method taking into account the matrix absorption effects. A total of 30 bones from 13 individuals, buried between the mid-XVlllth to early XIXth centuries, were analyzed to study the elemental composition and elemental distribution. The bones were collected from a church in Almada (Portugal), called Ermida do Espirito Santo, located near the Tagus River and at the sea neighbourhood. The triaxial geometry setup was used to quantify Ca, Fe, Cu, Zn, Br, Sr and Pb of powder pressed bone pellets (n=9 for each bone). Cluster analysis was performed considering the elemental concentrations for the different bones. There was a clear association between some bones regarding Fe, Cu, Zn, Br and Pb content but not a categorization between cortical and trabecular bones. The elemental distribution of Cu, Zn and Pb were assessed by the benchtop p.-analysis, the M4 Tornado, based on a polycapillary system which provides multi-elemental 2D maps. The results showed that contamination was mostly on the surface of the bone confirming that it was related to the burial shroud covering the individuals.

2016

Subsidence monitoring in the coastal region of Nigeria using multi temporal interferometric synthetic aperture radar (MT-Insar)

Autores
Mahmud, MU; Yakubu, TA; Adewuyi, TO; Sousa, JJ; Ruiz Armenteros, AM; Bakon, M; Lazecky, M; Perissin, D;

Publicação
European Space Agency, (Special Publication) ESA SP

Abstract
The uncontrolled exploitation of the groundwater, oil and gas in the Nigerian coastal geosyncline has led to progressive decline of the aquifer level and a continuous need for opening deeper drillings to exploit deeper aquifers. From the analysis of the interferometric results derived from the application of Multi-Temporal Interferometry (MT-InSAR) technique, Lagos state appears to be subsiding conically up to -7 mm/yr. The velocity rates of subsidence in the surrounding cities like Lekki, Badagry, Ikorodu and Epe are much higher than in Lagos city. These preliminary investigation results reveal heavy structures, in particular buildings, that were seen constructed mostly on the sand filled areas where the sediments compaction rates is very high.

2016

Remote supervision system for aquaculture platforms

Autores
Sousa e Silva, MSE; Cruz, NA; Lima, FP;

Publicação
OCEANS 2016 MTS/IEEE MONTEREY

Abstract
Aquaculture processes usually take place in remote and harsh environments, and are highly dependent on uncontrollable and unpredictable variables, therefore its monitoring and supervision can be a key factor in this activity. Taking that into account, this paper proposes a solution for a Remote Supervision System for Aquaculture Platforms, that contemplates a modular, reconfigurable and expandable sensor network based on the I2C protocol, which is composed by two different types of sensor nodes. The main sensor node, which serves as the sensor network coordinator and as a gateway, and the tiny sensor nodes, that are responsible for simple data collection tasks.

2016

Dynamic Switching Mechanism to Support Self-organization in ADACOR Holonic Control System

Autores
Leitao, P; Barbosa, J;

Publicação
IFAC PAPERSONLINE

Abstract
Evolvable control systems face the demands for modularity, decentralization, reconfigurabil-ity and responsiveness pointed out by the Industrie 4.0 initiative. In these systems, the self-organization model assumes a critical issue to ensure the correct evolution of the system structure into different operating configurations. ADACOR holonic manufacturing control architecture introduces an adaptive production control mechanism that balances between two states, combining the optimization provided by hierarchical structures with agility and responsiveness to condition changes offered by decentralized structures. This paper describes the switching mechanism that supports this dynamic balance and particularly the local and global driving forces for the self-organization model. The proposed model was experimentally tested in a small scale production system.

2016

2D Cloud Template Matching - A comparison between Iterative Closest Point and Perfect Match

Autores
Sobreira, H; Rocha, L; Costa, C; Lima, J; Costa, P; Moreira, AP;

Publicação
2016 IEEE INTERNATIONAL CONFERENCE ON AUTONOMOUS ROBOT SYSTEMS AND COMPETITIONS (ICARSC 2016)

Abstract
Self-localization of mobile robots in the environment is one of the most fundamental problems in the robotics field. It is a complex and challenging problem due to the high requirements of autonomous mobile vehicles, particularly with regard to algorithms accuracy, robustness and computational efficiency. In this paper we present the comparison of two of the most used map-matching algorithm, which are the Iterative Closest Point and the Perfect Match. This category of algorithms are normally applied in localization based on natural landmarks. They were compared using an extensive collection of metrics, such as accuracy, computational efficiency, convergence speed, maximum admissible initialization error and robustness to outliers in the robots sensors data. The test results were performed in both simulated and real world environments.

2016

PSF reconstruction validated using on-sky CANARY data in MOAO mode

Autores
Martin, OA; Correia, CM; Gendron, E; Rousset, G; Gratadour, D; Vidal, F; Morris, TJ; Basden, AG; Myers, RM; Neichel, B; Fusco, T;

Publicação
ADAPTIVE OPTICS SYSTEMS V

Abstract
CANARY is an open-loop tomographic adaptive optics (AO) demonstrator that was designed for use at the 4.2m William Herschel Telescope (WHT) in La Palma. Gearing up to extensive statistical studies of high redshifted galaxies surveyed with Multi-Object Spectrographs (MOS), the demonstrator CANARY has been designed to tackle technical challenges related to open-loop Adaptive-Optics (AO) control with mixed Natural Guide Star (NGS) and Laser Guide Star (LGS) tomography. We have developed a Point Spread Function (PSF)-Reconstruction algorithm dedicated to MOAO systems using system telemetry to estimate the PSF potentially anywhere in the observed field, a prerequisite to deconvolve AO-corrected science observations in Integral Field Spectroscopy (IFS). Additionally the ability to accurately reconstruct the PSF is the materialization of the broad and fine-detailed understanding of the residual error contributors, both atmospheric and opto-mechanical. In this paper we compare the classical PSF-r approach from Véran (1) that we take as reference on-Axis using the truth-sensor telemetry to one tailored to atmospheric tomography by handling the off-Axis data only. We've post-processed over 450 on-sky CANARY data sets with which we observe 92% and 88% of correlation on respectively the reconstructed Strehl Ratio (SR)/Full Width at Half Maximum (FWHM) compared to the sky values. The reference method achieves 95% and 92.5% exploiting directly the measurements of the residual phase from the Canary Truth Sensor (TS).

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