Export 9193 results:
Sort by: Author Title Type [ Year  (Desc)]
2016
Faias, Marta, Pedro Mota, Alberto Mulenga, and Joaquim P. Pina. "Asymmetry of ARCH effects and natural resources disease or virtue: Mozambique experience." AIP Conference Proceedings. 1738 (2016). AbstractWebsite

We study the exchange rate behavior, mainly as to the presence of asymmetry in the shocks to conditional variance. Particularly, we investigate if the presence of that asymmetric response is specific to a marked behavior of the currency, appreciation/Dutch disease/depreciation, and if it appears masked when taking long non-homogeneous periods. Taking Mozambique Metical bilateral exchange rate against South Africa Rand, a major trading partner, we identify specific movements in defined sub-periods, where the most recent has the Dutch disease under scrutiny. Our results point out that asymmetry emerges especially when the currency is depreciating, while it is masked when considering larger periods that combine differences in currency behavior.

M., Fernandes, Vygranenko Y., Vieira M., Lavareda G., Nunes Carvalho de C., and Amaral A. "Automated rf-PERTE system for room temperature deposition of TCO coatings." Energy Procedia . 102 (2016): 96.
Fernandes, M., Y. Vygranenko, M. Vieira, G. Lavareda, Nunes C. de Carvalho, and A. Amaral. "Automated rf-PERTE System for Room Temperature Deposition of TCO Coatings." Energy Procedia. 102 (2016): 96-101. Abstract

In this work we present a fully automated plasma-enhanced reactive thermal evaporation system (rf-PERTE) that can be used for the deposition of transparent metal oxide films without intentional heating of the substrate. The system and developed software enables the full control over critical deposition conditions such as mass flow of oxygen, process pressure, current flowing through crucible and rf-power. These parameters are automatically adjusted during the deposition thus keeping them in a narrow process window. This way, highly transparent and conductive coating can be deposited with a high degree of reproducibility of the optical and electrical characteristics. The resistivity of 9×10-4 Ω-cm and the peak transmittance of 90% in the visible spectral range were achieved for indium oxide films deposited on glass substrates. This technique is also suitable for the deposition of transparent conducting coatings in a wide range of plastic materials for flexible solar cells. In particular, we have successfully deposited indium oxide on PEN (polyethylene naphtalate) sheets with electrical and optical properties approaching the ones for films on glass.

Cunha, Jácome, Martin Erwig, Jorge Mendes, and João Saraiva. "Automatically Inferring Models from Spreadsheets." Automated Software Engineering (ASE). 23.3 (2016): 361-392. Abstractase14.pdfWebsite

Many errors in spreadsheet formulas can be avoided if spreadsheets are built automatically from higher-level models that can encode and enforce consistency constraints in the generated spreadsheets. Employing this strategy for legacy spreadsheets is difficult, because the model has to be reverse engineered from an existing spreadsheet and existing data must be transferred into the new model-generated spreadsheet. We have developed and implemented a technique that automatically infers relational schemas from spreadsheets. This technique uses particularities from the spreadsheet realm to create better schemas. We have evaluated this technique in two ways: First, we have demonstrated its applicability by using it on a set of real-world spreadsheets. Second, we have run an empirical study with users. The study has shown that the results produced by our technique are comparable to the ones developed by experts starting from the same (legacy) spreadsheet data. Although relational schemas are very useful to model data, they do not fit well spreadsheets as they do not allow to express layout. Thus, we have also introduced a mapping between relational schemas and ClassSheets. A ClassSheet controls further changes to the spreadsheet and safeguards it against a large class of formula errors. The developed tool is a contribution to spreadsheet (reverse) engineering, because it fills an important gap and allows a promising design method (ClassSheets) to be applied to a huge collection of legacy spreadsheets with minimal effort.

Moretto, Susana, Douglas Robinson, Jens Schippl, and António Brandão Moniz. "Beyond visions: survey to the high-speed train industry." Transportation Research Procedia. 2016.14 (2016): 1839-1846. AbstractWebsite

In Europe, the technology development of high-speed trains is increasingly exposed to societal needs, driven by ICT advancements, external to traditional design. Together with the liberalisation of the rail markets and increase pressures from other transport modes leads to an unprecedented situation where planers, operators and suppliers of high-speed have to take decision in this complex and competitive environment.
In such broadening of elements influencing design and, thus, product development process, from the survey here to be presented, it was not observed technology options assessment or strategic agenda setting from visions shifting in the same way.
For the high-speed train industry this new trend requires going beyond the visions of the past 15 to 20 years’ practices of “sector endogenous” and structurally closed strategic methods approaches to a broader interaction with the widening of societal actors now capable of being active contributors to innovation from digitalization.
This way to understand the European industry readiness for undertaking such supra systemic challenge, this paper presents the results from a survey conducted by the authors to 74 representatives of the high-speed train innovation chain regarding to which extent societal embedding is considered in the drafting of their visions and technology development projects.
This work becomes even more pertinent if considered that the debate is now open in the railway industry (not exclusive to high-speed trains) as they are launching the joint initiative SHIFT2RAIL, revise ERRAC (the European Rail Research Advisory Council) mandate and enter in a new research cycle with the European research framework Horizon 2020.

Coutinho, M. L., JP Veiga, L. C. Alves, J. Mirão, L. Dias, A. M. Lima, V. S. Muralha, and MF Macedo. "Characterization of the glaze and in-glaze pigments of the nineteenth-century relief tiles from the Pena National Palace, Sintra, Portugal." Applied Physics A: Materials Science and Processing. 122.7 (2016): 1-10. Abstract

© 2016, Springer-Verlag Berlin Heidelberg.The glaze and in-glaze pigments of the historical nineteenth-century glazed tiles from the Pena National Palace (Sintra, Portugal) were characterized using a multi-analytical approach. Chemical composition and microstructural characterization were ascertained by µ-PIXE, µ-Raman, optical microscopy and VP-SEM–EDS. The manufacturing technique and colour palette in these tiles were found to be close to the ceramic pigments used in traditional majolica. The blue and purple colours derive from cobalt oxide and manganese oxide, respectively. A mixture of Pb–Sn–Sb yellow with cobalt oxide and iron oxide was used for green and dark yellow, respectively, while grey tonalities consist of a complex mixture of cobalt oxide, manganese oxide and Pb–Sn–Sb yellow in different proportions. Results obtained allowed the determination of the oxides and elements used in pigments as well as production techniques, resorting to traditional majolica manufacture, although the tiles were produced by the end of the nineteenth century.

Morgado, M. L., and M. Rebelo. "Chebyshev Spectral Approximation for Diffusion Equations with Distributed Order in Tim." International Conference on Differential & Difference Equations and Applications. 2016.
Calvet, Laura, Albert Ferrer, Isabel M. Gomes, Angel A. Juan, and David Masip. "Combining statistical learning with metaheuristics for the multi-depot vehicle routing problem with market." Computers & Industrial Engineering. 94 (2016): 93-104. Abstract2016_calvetferrergomesjuanmasip.pdfWebsite

n/a

Lapi, Massimo, Daniele Martini, Emilio Zagli, Maurizio Orlando, Antonio Ramos, and Paolo Spinelli. "Comparison of flat slab strengthening techniques against punching-shear." Proceedings of The New Boundaries of Structural Concrete 2016, NBSC2016, Italy ACI Chapter. Capri, Italy: Italy ACI Chapter, 2016. Abstract

Punching-shear capacity of slab-column connections in existing R/C structures may be inadequate to bear design loads, so strengthening works are required. The lack of punching resistance may be due to detailing, design or building errors; in other cases, such lack is due to a change of use, which requires an increase of resistance. Different techniques have been developed for strengthening R/C slabs against punching: enlargement of the support, gluing external fibre reinforced polymers or casting a bonded concrete overlay (BCO) on the slab's top surface, insertion of post-installed steel bolts, application of fibre reinforced polymers cords as shear reinforcement. In the paper, the authors apply the Critical Shear Crack Theory (CSCT) to all of these techniques and evaluate their efficacy with reference to a case study.

Ramos, António Pinho. "Comportamento de Lajes Fungiformes Sujeitas a Acções Horizontais Cíclicas." Construção Magazine.76 (2016): 44-45.
Santos, F., C. Cismasiu, R. Perdigão, V. Bernardo, J. Sampayo, P. Candeias, A. Costa, A. Carvalho, and L. Guerreiro COMPORTAMENTO SÍSMICO DE LIGAÇÕES EM PASSADIÇOS PRÉ-FABRICADOS. 10º Congresso Nacional de Sismologia e Engenharia Sísmica. Ponta Delgada, 2016.artigosismica2016_submetido.docx
Lopes, Rui Amaral, João Martins, Daniel Aelenei, and Celson Pantoja Lima. "A cooperative net zero energy community to improve load matching." Renewable Energy. 93.August (2016): 1-13. AbstractWebsite

The work reported here addresses load matching improvement in Net Zero Energy Buildings (Net-ZEBs). The related relevant literature shows that currently research work is mainly focused on improving the load matching of individual buildings. In this paper the concept of a Cooperative Net Zero Energy Community (CNet-ZEC) is introduced, extending discussion to the enhancement of load matching at a wider community level. Both building and community levels are compared in order to assess the work proposed here, through the analysis of three distinct scenarios where five Net-ZEBs work individually or in community.

The results presented here were obtained through a detailed simulation based on 1-min resolution stochastic load profiles and recorded weather data. The results indicate that over the period of a year the CNet-ZEC has the potential to increase the electrical demand covered by onsite electricity generation up to 21% and the on-site generation that is used by the building up to 15%. The following elements are considered by the CNet-ZEC in order to produce those results: (i) demand heterogeneity of the buildings integrating the community; (ii) the higher number of controllable devices; and (iii) the potential higher amount of energy available to satisfy the community demand.

Brás, C., G. Eichfelder, and J. Júdice. "Copositivity tests based on the Linear Complementarity Problem." Computational Optimization and Applications. 63.2 (2016): 461-493. AbstractWebsite

We present copositivity tests based on new necessary and sufficient conditions which require the solution of linear complementarity problems (LCP). We propose methodologies involving Lemke’s method, an enumerative algorithm and a linear mixed-integer programming formulation to solve the required LCPs. Moreover, we discuss a new necessary condition for (strict) copositivity based on solving a linear program, which can be used as a preprocessing step. The algorithms with these three different variants are thoroughly applied to test matrices from the literature and to max-clique instances with matrices of order up to 496×496. We compare our procedures with three other copositivity tests from the literature as well as with a general global optimization solver. The numerical results are very promising and equally good and in many cases better than the results reported elsewhere.

Hansen, Bitten Bolvig, Jesper Milàn, Lars B. Clemmensen, Jan Schulz Adolfssen, Eliza Jarl Estrup, Nicole Klein, Octávio Mateus, and Oliver Wings. "Coprolites from the Late Triassic Kap Stewart Formation, Jameson Land, East Greenland: morphology, classification and prey inclusions." Geological Society, London, Special Publications. 434.1 (2016): 49-69. Abstracthansen_et_al_2015_coprolites_from_the_late_triassic_kap_stewart_formation_jameson_land_east_greenland.pdfWebsite

A large collection of vertebrate coprolites from black lacustrine shales in the Late Triassic (Rhaetian–Sinemurian) Kap Stewart Formation, East Greenland is examined with regard to internal and external morphology, prey inclusions, and possible relationships to the contemporary vertebrate fauna. A number of the coprolites were mineralogically examined by X-ray diffraction (XRD), showing the primary mineral composition to be apatite, clay minerals, carbonates and, occasionally, quartz in the form of secondary mineral grains. The coprolite assemblage shows multiple sizes and morphotypes of coprolites, and different types of prey inclusions, demonstrating that the coprolite assemblage originates from a variety of different producers.Supplementary material: A description of the size, shape, structure, texture, contents and preservation of the 328 specimens is available at https://doi.org/10.6084/m9.figshare.c.2134335

Faustino, Pedro, and Carlos Chastre. "Damage Effect on Concrete Columns Confined with Carbon Composites." ACI Structural Journal. 113 (2016). AbstractWebsite

Five experimental cyclic tests were carried out on reinforced concrete rectangular columns with rounded corners, different condition (new and damaged) and different strengthening systems: that included confinement through carbon fiber (CFRP) jackets, anchor dowels, high strength repair mortar and external longitudinal stainless steel bars. Lateral load - displacement relationship, energy dissipation, ductility and curvature results were analyzed together with two different damage assessment classifications. The overall evaluation concludes that the use of external confinement with CFRP on RC columns is viable and of effective performance enhancement alone and combined with other techniques. Damaged columns that were retrofitted showed an increased load capacity up to 20% along with good ductile behavior within the limits of the US, European, Canadian and Japanese codes, with minor/moderate degree of damage at 1% drift ratio and moderate degree of damage at 2% drift ratio.

Vieira, Manuel V. C. "Derivatives of eigenvalues and Jordan frames." Numerical Algebra, Control and Optimization. 6.2 (2016): 115-126.
Fernandes, Miguel D., Luis B. Oliveira, João Goes, and João P. Oliveira Design of a Low Phase Error Multiphase Clock Generator for Modern Wideband Receivers. IEEE 12th Conference on PhD Research in Microelectronics and Electronics (PRIME 2016). Lisbon, Portugal: IEEE, 2016.
Tschopp, E., and O. Mateus. "Diplodocus Marsh, 1878 (Dinosauria, Sauropoda): proposed designation of D. carnegii Hatcher, 1901 as the type species." Bulletin of Zoological Nomenclature. 73.1 (2016): 17-24. Abstracttschopp_mateus_2016_-_case_3700_-_diplodocus_type.pdf

The purpose of this application, under Articles 78.1 and 81.1 of the Code, is to replace Diplodocus longus Marsh, 1878 as the type species of the sauropod dinosaur genus Diplodocus by the much better represented D. carnegii Hatcher, 1901, due to the undiagnosable state of the holotype of D. longus (YPM 1920, a partial tail and a chevron). The holotype of D. carnegii, CM 84, is a well-preserved and mostly articulated specimen. Casts of it are on display in various museums around the world, and the species has generally been used as the main reference for studies of comparative anatomy or phylogeny of the genus. Both species are known from the Upper Jurassic Morrison Formation of the western United States. The genus Diplodocus is the basis for the family-level taxa diplodocinae Marsh, 1884, diplodocidae Marsh, 1884, diplodocimorpha Marsh, 1884 (Calvo & Salgado, 1995) and diplodocoidea Marsh, 1884 (Upchurch, 1995). It is also a specifier of at least 10 phylogenetic clades. With the replacement of D. longus by D. carnegii as type species, Diplodocus could be preserved as a taxonomic name with generally accepted content. Taxonomic stability of the entire clade diplodocoidea, and the proposed definitions of several clades within Sauropoda, could be maintained.

Ricardo, L., A. Amaral, Nunes C. de Carvalho, and G. Lavareda. "Dopant transfer from poly-si thin films to c-Si: An alternative technique for device processing." Materials Science in Semiconductor Processing. 42.2 (2016): 210-214. Abstract

An alternative technique for production of devices which uses both silicon crystalline wafers (p-type) and heavy doped amorphous silicon thin films (n-type) is reported. The amorphous silicon acts as a finite source of dopant and is deposited (at low temperature, 70 °C) by plasma enhanced chemical vapor deposition on silicon wafers. Afterwards, the process of dopant diffusion into the crystalline silicon occurs in a diffusion furnace at 1000 °C for 2 h, to create p–n junctions. Using SIMS analyses, a dopant (P) transfer into c-Si of about 30% is verified and 87% of the dopant transferred is electrically active. Consequently, n-MOSFET devices are produced using a gate oxide thermally grown at the same diffusion temperature for one hour. The preliminary results of the MOSFET (channel length and width of 0.5 and 5 mm, respectively) show a depletion behavior with a threshold voltage, Vth=−8.2 V and afield-effect mobility, µFE=187.8 cm2/(Vs).

L., Ricardo, Amaral A., Nunes Carvalho de C., and Lavareda G. "Dopant transfer from poly-Si thin films to c-Si: an alternative technique for device processing"." Materials Science in Semiconductor Processing . 42 (2016): 210.
Cardoso, M. M., I. N. Peca, C. D. Raposo, K. T. Petrova, M. T. Barros, R. Gardner, and A. Bicho. "Doxorubicin-loaded galactoseconjugated poly(d,l-lactide-co-glycolide) nanoparticles as hepatocyte-targeting drug carrier." J. Microencapsul. 33.4 (2016): 315-322. DOI: 10.1080/02652048.2016.1185474.