Vieira Ferreira L.F.,University of Lisbon |
Conceic ao D.S.,University of Lisbon |
Ferreira D.P.,University of Lisbon |
Santos L.F.,University of Lisbon |
And 3 more authors.
Journal of Raman Spectroscopy | Year: 2014
The first archaeological evidence reported for tile production in Portugal was discovered in Santo António da Charneca (SAC), late 15th or early 16th centuries' pottery kiln, south riverside of Tagus River. Samples from this kiln were studied with the use of non-invasive spectroscopies, namely, μ-Raman, ground-state diffuse reflectance absorption, Fourier transform infrared and particle-induced X-ray or X-ray fluorescence emission. These results were compared with the ones obtained for coeval tiles produced in Seville, Spain, originated from Portuguese archaeological sites, because it is well know that the Portuguese King Manuel the First imported in 1498 signi ficant quantities of those tiles to decorate several palaces. The obtained results provided new spectroscopic insights, used to establish similarities but also clear differences regarding the SAC and the coeval Seville tiles found in Portugal. White glaze from both tiles gave evidence about the use of tin oxide as whitening agent and lead oxide as glassy agent. Cobalt oxides were also used as blue pigments in the two production centres. The brown and amber pigments in the samples from SAC derive from the manganese oxides dispersed in the lead-tin glaze, and kentrolite crystals were identified by μ-Raman in these tiles. In the arista and cuerda-seca tiles from Seville, diopside was detected. Divalent copper also exists in the green glaze matrix but in small amounts, which did not allow the Raman detection of the copper compound's microcrystals. However, diffuse reflectance measurements point to malachite green as responsible of green coloration. The Seville pastes contain calcium carbonate, although the SAC pastes do not evidence significant amounts of that compound in its composition. All the SAC pastes evidenced a high silica level, and quartz and anatase were clearly detected in the paste and possibly kaolinite. The Raman signals of orthoclase and calcium carbonate were detected in the Seville tiles. Copyright © 2014 John Wiley & Sons, Ltd.
Zare M.,University of Tehran |
Panagopoulos T.,University of Algarve |
Loures L.,Polytechnic Institute of Portalegre
Land Use Policy | Year: 2017
Predicting soil erosion potential is important in watershed management. A rapidly growing Iranian population and climate change are expected to influence land use and soil sustainability. In recent years, northern Iran has experienced significant land use changes due to internal migration along the Caspian coast and conversion of forests and rangelands. Considering the effect of these changes in the future, the purpose of this study is to forecast land use patterns and investigate soil erosion scenarios using the Revised Universal Loss Equation and Markov Cellular Automata. Data from 1981 to 2011 were used as a baseline to estimate changes that might occur in 2030. The results reveal that the mean erosion potential will increase 45% from the estimated 104.52 t ha−1 year−1 in the baseline period. Moreover, the results indicate that land use change from forest area to settlements will be the most significant factor in erosion induced by land use change, showing the highest correlation among erosional factors. Projecting land use change and its effect on soil erosion indicate that conversion may be unsustainable if change occurs on land that is not suited to the use. The method predicts soil erosion under different scenarios and provides policymakers a basis for altering programs related to land use optimization and urban growth. Those results indicated the necessity of appropriate policies and regulations particularly for limiting land use changes and urban sprawl in areas of unfavorable soil erosion risk factors. © 2017 Elsevier Ltd
Ferreira P.,University of Évora |
Ferreira P.,Polytechnic Institute of Portalegre
Physica A: Statistical Mechanics and its Applications | Year: 2016
The objective of this paper is to analyze if the Euro crisis, which started in 2009, changes the cross-correlation pattern of bank shares with the national stock indexes in both in Eurozone and non-Eurozone countries. We study all banks listed in the main stock indexes of European Union countries, applying the detrended cross-correlation coefficient. An increase in the correlation indicates that the banking sector now has a greater influence in the national index, while a decrease in the correlation means the opposite. Our results show that 19 of the 39 banks analyzed in the Eurozone increased their correlation with national indexes, whilst in the non-Eurozone countries this happened with 14 of the 24 studied banks. While some authors argue that the crisis may have been aggravated by the weight of banks in the economy, Eurozone policy makers should pay attention to this feature. © 2016 Elsevier B.V.
Brito P.S.D.,Polytechnic Institute of Portalegre |
Patricio S.,Polytechnic Institute of Portalegre |
Rodrigues L.F.,Polytechnic Institute of Portalegre |
Sequeira C.A.C.,University of Lisbon
Surface and Coatings Technology | Year: 2012
The recovery of metallic ions by electrodeposition from solutions resulting from lixiviation of spent Zn-MnO 2 batteries was studied in an attempt to optimize the electrodeposition process, selectivity of ion-separation, morphologic characteristics and anticorrosive and galvanic properties of metallic deposits. The simultaneous deposition of zinc and manganese on different ferrous substrates under various experimental conditions was tested to access the efficiency of the electrodeposition, the morphology and composition of metallic deposits as well as their performance as galvanic coating layers. The effect of additives, namely, boric acid and methylamine, on the properties of produced covering layers was also studied. Results show that solutions resulting from hydrometallurgical treatment of spent domestic Zn-MnO 2-batteries can be processed directly as electrodeposition baths for the recovery of zinc alloys. The presence of additives, such as boric acid and methylamine, with buffering or passivating effects, does improve the simultaneous deposition of Mn. © 2011 Elsevier B.V.
Francisco S.M.,University of Lisbon |
Veiga Simao A.M.,University of Lisbon |
Ferreira P.C.,University of Lisbon |
Martins M.J.D.D.,Polytechnic Institute of Portalegre
Computers in Human Behavior | Year: 2015
The purpose of this study was to investigate how university students perceive their involvement in the cyberbullying phenomenon, and its impact on their well-being. Thus, this study presents a preliminary approach of how college students' perceived involvement in acts of cyberbullying can be measured. Firstly, Exploratory Factor Analysis (N = 349) revealed a unidimensional structure of the four scales included in the Cyberbullying Inventory for College Students. Then, Item Response Theory (N = 170) was used to analyze the unidimensionality of each scale and the interactions between participants and items. Results revealed good item reliability and Cronbach's α for each scale. Results also showed the potential of the instrument and how college students underrated their involvement in acts of cyberbullying. Additionally, aggression types, coping strategies and sources of help to deal with cyberbullying were identified and discussed. Lastly, age, gender and course-related issues were considered in the analysis. Implications for researchers and practitioners are discussed. © 2014 Elsevier Ltd. All rights reserved.
Nunes P.M.,University of Beira Interior |
Nunes P.M.,University of Évora |
Serrasqueiro Z.,University of Beira Interior |
Serrasqueiro Z.,University of Évora |
Leitao J.,Polytechnic Institute of Portalegre
Research Policy | Year: 2012
To investigate whether there is a similar relationship between R&D intensity and growth in high-tech and non-high-tech small and medium-sized enterprises (SMEs), we examine two samples of SMEs in manufacturing industries, applying the two-step estimation method. Our findings are that R&D intensity restricts the growth of high-tech SMEs at lower levels of R&D intensity and stimulates their growth at higher levels. However, R&D intensity restricts the growth of non-high-tech SMEs regardless of the level of R&D. The relationships obtained between other determinants considered in the literature and the growth of high-tech and non-high-tech SMEs allow us to conclude that (i) smaller, younger, non-high-tech SMEs grow more quickly than larger, older, non-high-tech SMEs, which does not occur in the case of high-tech SMEs; and (ii) financing restrictions are especially important in financing the growth of high-tech SMEs, compared with non-high-tech SMEs. © 2011 Elsevier B.V. All rights reserved.
Oliveira J.F.,Polytechnic Institute of Portalegre
2013 8th International Conference on Information Technology in Asia - Smart Devices Trend: Technologising Future Lifestyle, Proceedings of CITA 2013 | Year: 2013
In an ideal world, blind people could navigate any new route without training, travel by underground/metro during rush hour without problems, and explore with confidence. Environments can be diverse and dynamic and unfortunately no universal gadget-aid solution yet exists to help navigation. Advances in mobile phone technology and entertainment devices such as the Kinect are allowing for new application scenarios to arise. In this paper, a system that could help interface a person to a wide range of environments is presented. The Path Force Feedback Belt system takes at a fixed rate dual images of the environment using a mobile device, it reconstructs a 3D model of the surroundings, and extracts features such as sidewalk corners, walls, and obstacles. The mobile device then determines which of the force feedback actuators on a 360° belt worn on the waist has to be signaled, hence providing path feedback. © 2013 IEEE.
Loures L.,Polytechnic Institute of Portalegre |
Loures L.,Center for Spatial and Organizational Dynamics
Habitat International | Year: 2015
Generally located in advantageous locations near city centers or along waterfronts and supported by existing infrastructure, post-industrial landscapes constitute environmentally impaired resources that need to be returned to productive uses, and reintegrated into the surrounding community. However, the complexity of any post-industrial redevelopment project, evident in the number of different ways in which it is described both in the literature and by designers and developers who work and/or analyze these landscapes make post-industrial redevelopment difficult to accomplish. Considering the purpose of the present research, it was necessary to use several methods throughout the investigation, including quantitative and qualitative research methods divided in two main sections: literature review and case study research. Considering the collected data and the performed statistical analysis, it is possible to conclude that, thought there are strong relationships between several of the identified benefits and barriers, the survey revealed distinct perceptions about the benefits and the barriers associated to post-industrial redevelopment between the general public (i.e. redeveloped post-industrial site users) and redevelopment experts, idea which is of utmost importance considering that designers tend to be primarily focused on aesthetics, leaving society's other main goals to secondary status, and that planning and landscape redevelopment activities are increasingly becoming less the result of design and more the expression of economic and sociocultural forces. Moreover the performed analysis showed that while for the general public the main barriers to post-industrial redevelopment are the potential for biological, physical and chemical impacts, and the uncertainty about liability and cleanup issues; for experts the main barriers are the high redevelopment costs; and the challenges in obtaining financial support. Regarding the main benefits while for the general public, the creation of open green spaces and the creation of jobs are the most important ones, for experts they are associated with the possibility to reduce urban sprawl, and encourage recreation and connectivity. © 2014 Elsevier Ltd.
Calha A.,Polytechnic Institute of Portalegre
Saude e Sociedade | Year: 2015
The extended increasing of life expectancy associated with a significant decline in the birth rate have contributed to a rapid aging of societies and a profound change in the demographic structure of many European countries. We analyze in this article the specific condition of the senior in the countries of Southern Europe and Scandinavia. In the case of countries with a configuration of different models of social protection, we realize that there are different ways of living old age in these societies. For this reason, our analysis uses the results obtained in the European Social Survey (round 5-2010). The analysis reveals the existence of different models that set the senior condition in the referred societies, which means different ways of dealing with the aging process. To conclude, the condition of the elderly does not depend solely on biological factors related to physical limitation, it is also influenced by social configuration that fits the experience of this period of individual life, as well as the way old people face it. © 2015 UNIV SAOPAULO. All rights reserved.
Lourinho G.,Polytechnic Institute of Portalegre |
Brito P.,Polytechnic Institute of Portalegre
Energy | Year: 2015
This work focuses on assessing the potential for generation of biomass residues from agroforestry sources in a region of Portugal (Alto Alentejo), within the scope of energy valorization of the biomass by means of combustion technologies. The model uses a GIS-based method to estimate the technical potential of biomass based on current cartographic and statistical data. The analyzed components related to the biomass potential are: effective biomass area (in ha), biomass availability (in dry t/year) and energy potential (in GJ/year). The potential of agricultural and forest residues in Alto Alentejo is estimated to be 4000 dry t/year and 40,000 dry t/year, respectively. This amount of biomass corresponds to an energy potential of 158,000GJ/year, which is equivalent to 100% of the combined consumption of electricity in three out of the nine municipalities covered in this study. A preliminary analysis on the suitability of the location and characteristics of a 9MW biomass power plant in the region is made; alternative solutions and most representative species are also discussed. It was concluded that not enough biomass is available to supply the energy facility and that the most promising option for the region is the combustion of residues in small scale units. © 2014 Elsevier Ltd.