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Vila Nova de Famalicão, Portugal

Araujo A.,University Lusiada Of Vila Nova Of Famalicao | Silvano S.,University of Aveiro | Martins N.,University of Aveiro
Infrared Physics and Technology | Year: 2014

The Monte Carlo statistical method was used to estimate the uncertainty of the emissivity, obtained by dual spectral infrared radiometry, of gray surfaces at ambient temperature. A large number of simulations were carried out, by selecting a wide range of values from parameters that directly affect the resulting emissivity: the emissivity of the target surface, the background temperature of the surrounding surfaces, the maximum error of the detectors, and the width and spectral location of the bands of the detectors. In summary, the level of uncertainty grows very quickly as the background temperature approximates the target surface. In terms of the spectral characteristics of the detectors, it was found that narrow bands, far apart from each other, and short wavelength bands provide the lowest uncertainty from all simulated emissivity values. © 2014 Elsevier B.V. All rights reserved. Source


Quinteiro P.,University of Aveiro | Dias A.C.,University of Aveiro | Araujo A.,University Lusiada Of Vila Nova Of Famalicao | Pestana J.L.T.,University of Aveiro | And 2 more authors.
International Journal of Life Cycle Assessment | Year: 2015

Purpose: High concentration of suspended solids (SS)—fine fraction of eroded soil particles—reaching lotic environments and remaining in suspension by turbulence can be a significant stressor affecting the biodiversity of these aquatic systems. However, a method to assess the potential effects caused by SS on freshwater species in the life cycle impact assessment (LCIA) phase still remains a gap. This study develops a method to derive endpoint characterisation factors, based on a fate and effect model, addressing the direct potential effects of SS in the potential loss of aquatic invertebrate or algae and macrophyte species. Methods: Characterisation factors for the assessment of the direct effects of SS in the potential disappearance of macroinvertebrates, algae and macrophytes in 22 different European river sections were derived by combining both fate and effect factors. Fate factors reflect the environmental residence time of SS in river sections per unit of water volume in this same section. Effect factors were calculated from an empirical relationship between the potentially disappeared fraction (PDF) of aquatic species and the concentration of SS. These factors were determined based on a concentration-response function, on gross soil erosion data and detrimental concentrations of SS for different taxa in river sections. Results and discussion: The product of fate with effect factors constitutes the characterisation factors for both macroinvertebrates, algae and macrophytes. The estimated EFs are higher for macroinvertebrates in almost all river sections under study, showing that the potential effects caused by SS throughout the water column are higher for macroinvertebrates than for algae and macrophytes. For macroinvertebrates, characterisation factors range between 2.8 × 10− 7 and 3.1 × 10− 3 PDF m3 day mg−1, whereas for algae and macrophytes, they range between 1.6 × 10− 7 and 4.7 × 10− 4 PDF m3 day mg−1. Conclusions: The developed method and the derived characterisation factors enable a consistent assessment and comparison of the potential detrimental effects of SS on aquatic invertebrate and macrophyte communities at different locations. Long-term, on-site monitoring of SS levels in the water column should be performed to understand the magnitude of the effects of SS on aquatic biota and to determine the taxa that are more sensitive to the SS stressor. This monitoring will improve the robustness of the proposed LCA method, the reliability of the characterisation factors, as well as the development of characterisation factors for a wider range of rivers. © 2015, Springer-Verlag Berlin Heidelberg. Source


Araujo A.,University Lusiada Of Vila Nova Of Famalicao | Martins N.,University of Aveiro
Measurement Science and Technology | Year: 2015

The Monte Carlo technique for uncertainty propagation was used to estimate the uncertainty of ambient temperature measurements, obtained by dual-band pyrometry, of assumed grey surfaces. A large number of simulations were performed for a wide range of values from the following parameters: uncertainty of the detectors, emissivity of the target surface, background temperature of the surrounding surfaces, and spectral characteristics of the detectors (bandwidth, location of the bands, and distance between bands). Temperature measurement uncertainties from single-band pyrometry were also simulated for evaluation against dual-band uncertainties. It is concluded that the following parameters minimize dual-band temperature uncertainty: narrow wavelength bands, far apart from each other, positioned towards low wavelengths; low surface emissivity; high or low background temperature with respect to the target surface temperature (uncertainty grows very fast as the background and target temperatures converge, and tends to a constant minimum value as the background and target temperatures diverge). © 2015 IOP Publishing Ltd. Source


Cardoso A.,Universdiade Portucalense | Moreira F.,Universdiade Portucalense | Moreira F.,University Lusiada Of Vila Nova Of Famalicao | Simoes P.,University of Coimbra
Advances in Intelligent Systems and Computing | Year: 2014

The cloud computing paradigm is transforming the way IT services are provided and consumed. The moving of in-house IT services to the cloudcomputing paradigm should be performed carefully lest cause high losses in the institution that is in the process of transition to cloud computing. So, in this paper, we presents a study of several frameworks developed to move IT services and applications to the cloud computing. The work ends with a summary description of the proposed solution, by the same authors, to the migration of services, applications, data and infrastructures to cloud computing. The solution encompasses a framework with a set of processes that are supported by the Information Technology Infrastructure Library (ITIL). © Springer International Publishing Switzerland 2014. Source


Quinteiro P.,University of Aveiro | Dias A.C.,University of Aveiro | Araujo A.,University Lusiada Of Vila Nova Of Famalicao | Pestana J.L.T.,University of Aveiro | And 2 more authors.
International Journal of Life Cycle Assessment | Year: 2016

This is a corrigendum and clarification on behalf of the authors. Figure 1 in the original version of this article has been corrected as follows: (Table presented.). © Springer-Verlag Berlin Heidelberg 2016. Source

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